No title

ISSUE SIX APRIL 2008

€5.00 / £3.50 ISSN 1757-2517

THE MAGAZINE FOR SMALL SCIENCE

MIRACLE MATERIAL Carbon nanotubes

Nobel conversation The future for Sir Harry Kroto

Smart Yarns Spinning next generation materials

Plumbing on the nanoscale Welding nanotubes together for smart circuits

Credit crunch How market changes will impact nanotech

Investing in the future Japan on a mission to stay top in technology

What’s New in Nano Keep up with the latest news

PLUS: A TRICK OF THE LIGHT? METAMATERIALS BENDING LIGHT BACKWARDS

TS N E NT O C

Subscribe to nano for only £36 for 10 issues! UK - £36, Europe - €65, USA & Far East - $98, Australia - AU$105 Title:.......................Initial: ........................... Surname: ........................................................................................................ Job Title: ......................................................................................................... Company Name: ........................................................................................... Address: ......................................................................................................... ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... Post Code: .............................Country: ........................................................ Email: ............................................................................................................. Telephone: .....................................................................................................

Two ways to pay:Cheque made payable to IoN Publishing Ltd Visa/Switch/Mastercard Card Number: Expiry Date:

Issue Number (switch only):

Signature: ....................................................Date: ......................................... Please duplicate form and post to: Nano, IoN Publishing, 6 The Alpha Centre, Stirling University Innovation Park, Stirling FK9 4NF Scotland UK. Email: [email protected]. Tel: +44 (0)1786 447520 Fax: +44 (0)1786 447530

FREE ONLINE SUBSCRIPTION. Contact [email protected] for more infor mation

In the next issue: The Developing World: From energy resources to agriculture to medicine, nanotechnology is set to have a major impact on progress in the less developed world. This special issue highlights some new technologies being developed to clean water, eliminate disease and improve energy efficiency in developing nations. What’s new in Nano? Nanomedicine, ethics… and lots more 002


nano

nano Issue 6 April 2008 Editor:

Advertising:

Elaine Mulcahy

[email protected]

elaine.mulcahy@ nanomagazine.co.uk

Subscriptions

+44 (0)1786 447520

Gemma McCulloch

IoN Publishing Ltd

[email protected] +44 (0)1786 447520

Design: [email protected] Contributors Kshitij Aditeya Singh, Institute of Nanotechnology. Sir John Pendry, Imperial College London. Nader Engheta, University of Pennsylvania. Ray Baughman, University of Texas in Dallas. Edward Wright, British Embassy in Tokyo. Ottilia Saxl, Institute of Nanotechnology. Kazu Suenaga and Dr Chuanhong Jin National Institute of Advanced Industrial Science and Technology, Japan. Maria Losurdo, University of Bari. Norbert Esser, Institute for Analytical Sciences. Richard Moore, Institute of Nanotechnology. Pythagoras Petratos, University of London ©2008 IoN Publishing Ltd 6 The Alpha Centre Stirling University Innovation Park Stirling FK9 4NF Scotland

012

FEATURES

COUNTRY PROFILE Nanotechnology in Japan ...................024

Carbon nanotubes ...............................012

Big investment to stay top in technology

Applications and Markets

A trick of the light? .............................016

016

COMMENT Financial markets ................................040

Professor Sir John Pendry explains

How the current economic crisis will effect

metamaterials and negative refraction

nanotechnology development Smart Yarns...........................................020 Scaffolds for growing skin and nerves just

020

INTERVIEW Nobel Conversation ............................028

some of the potentials of this technology

Ottilia Saxl speaks to Sir Harry Kroto Plumbing carbon nanotubes .............032

REGULARS

Novel technologies for welding tubes together like water pipes

032

Editorial.................................................004 Events ....................................................006

Ellipsometry and Polarimetry ...........034

What’s new in nano .............................008

New techniques for understanding and

Nanomedicine ......................................038 Keeping things in perspective

predicting the properties of nanoparticles and nanocomposites

034

Nanoart..................................................043

003

L IA R ITO D E

Nanotechnology and miracle materials

Elaine Mulcahy PhD, Editor

arbon nanotubes are likely to impact a huge range of structures, technologies, materials, medicines and markets over the coming years. It is impossible to cover it all or indeed to measure the significance this material will have on future generations. Smart clothing will change the experience an astronaut has in space, while photovoltaic cells will harvest solar energy on earth. The possibilities extend to all areas of science from engineering to medicine and textiles to energy generation.

C

So what makes carbon nanotubes so special? Firstly, they are unique, possessing properties that seem impossible and push the boundaries of science. Their strength is a good example. A “ribbon” of carbon nanotube may weigh just one sixth that of a comparable ribbon of steel. But the nanotube is 100 times stronger. This property alone opens a range of possibilities – super strong structures that are also very light, such as the outer surface of a space shuttle or coatings for automobiles. More futuristic is the possibility of a space elevator, which researchers around the globe are now racing to build. If successful, a cable of carbon nanotube material will one day transport people and payloads into space.

004

In this issue of NANO we turn to carbon nanotubes. From their discovery to the opportunity and potential they offer to the demand for new technologies, we explore a range of areas impacted by this miracle material. Carbon nanotubes also possess amazing electronic, thermal and structural properties. They are as good as copper at conducting electricity, making them ideal candidates for future computer chips and circuits, for example, that will operate in the nanoscale. The list goes on. Kshitij Aditeya Singh from the Institute of Nanotechnology provides further insight in this issue, listing a range of current and potential applications and technologies that utilise carbon nanotubes as well as an insight into markets that will be influenced by the technology. Discovery Research and development of carbon nanotubes technologies have exploded since the early 1990s following the discovery and characterisation of the soccer ball-shaped carbon C60 fullerene molecule

in 1985. Buckyballs are sphericallyshaped fullerenes, while carbon nanotubes are cylindrical. We are privileged in this issue to include an interview with Professor Sir Harry Kroto FRS (University of Sussex), who was awarded the Nobel Prize for Chemistry in 1996 along with Robert F Curl and Richard E Smalley (Rice University) for their discovery of fullerenes. He spoke to the Institute of Nanotechnology’s Ottilia Saxl about his predictions for big changes in civil engineering and discusses moves to encourage communication among the next generation of scientists. Scaffolds and plumbing Research at the laboratories of Professor Ray Baughman at the University of Texas in Dallas is leading the world in applications to create new materials using spinning


nano techniques for extracting “yarns” from nanotube forests. The use of nanotube sheets and yarns as scaffolds for growing skin and nervous tissue as well as harvesting energy and building artificial muscles are some of the new technologies being developed that we present in this issue of NANO. Also discussed are novel techniques for “plumbing” nanotubes together like water pipes, which are being developed at Japan’s National Institute of Advanced Industrial Science and Technology. Such techniques have the potential to enable the creation of nanotube circuits which could radically change electronics. Japan is our profiled country in this issue. Determined to maintain its place as a technology leader, the country is investing billions in nanotechnology. The Council for Science and Technology 2008 budget recently revealed planned investment of 86.5 billion yen (equivalent to half a billion euro) in nanotechnology and materials. This is up five percent on previous years. Japan is also investing heavily in other key priority areas of life sciences, energy, infrastructure, environment, manufacturing and space. Bending over backwards Diverging slightly from the theme of carbon nanotubes, we explore another fascinating material that appears to defy the laws of physics. Professor Sir John Pendry at Imperial College London provides an insight into metamaterials – materials with negative refractive index capable of bending light in seemingly impossible directions. As the field of nanotechnology advances, we may see a collision of the two materials (nano and meta) to create novel structures capable of bending light backwards. Much publicity has been given to the concept of an invisibility cloak which would exploit this technology but the potential applications are much greater than this. Pendry envisages devices capable of harvesting radiation and guiding signals around an optical chip. Indeed, as Nader Engheta explains, electronics could see significant miniaturisation of circuits in parallel with an increase in storage capacity as we switch to nano-scale circuitry capable of directing light (rather than electrons).

The increasing miniaturization of integrated circuits, along with advances in knowledge of structures at the nanoscale and the development of composite and smart materials demands the continuous development and enhancement of novel analytical techniques. Ellipsometry and polarimetry are two techniques gaining much attention due to their non-destructive, nanoscale sensitivity. The latest advances in these techniques are described by experts from NanoCharm, a new European consortium that will provide scientists and companies with leading edge tools to help them succeed in



this globally important and competitive nanotech market. Investment and markets Investments and markets are an uncertain entity. The subprime mortgage collapse in the US this year and the knock-on effect it has had across the globe has resulted in great disruption and uncertainty both at the high street bank and the stock markets. Progress in the new field of nanotechnology may also be squeezed by the credit crunch and we welcome the insight of Pythagoras Petratos from Queen Mary, University of London on markets and nanotech investment during these difficult times.

AS THE FIELD OF NANOTECHNOLOGY ADVANCES, WE MAY SEE A COLLISION OF THE TWO MATERIALS (NANO AND META) TO CREATE NOVEL STRUCTURES CAPABLE OF BENDING LIGHT BACKWARDS. MUCH PUBLICITY HAS BEEN GIVEN TO THE CONCEPT OF AN INVISIBILITY CLOAK WHICH WOULD EXPLOIT THIS TECHNOLOGY BUT THE POTENTIAL APPLICATIONS ARE MUCH GREATER THAN THIS. 005

S NT E EV

Events Calendar EVERY MONTH WE HIGHLIGHT THE KEY CONFERENCES AND SUMMITS WHERE INDUSTRY EXPERTS, ACADEMICS AND POLICY MAKERS CONVENE May 14-16

development in Micro- and Nano-scale

June 22-25

Biosensors 2008 Shanghai, China

phenomena, devices, systems,

ANM 2008 Aveiro, Portugal

The tenth world congress on biosensors

manufacturing, as well as the

The 2nd International Conference on

will feature presentations on topics

commercialization of Micro- and

Advanced Nano Materials brings together

ranging from DNA chips and nucleic acid

Nano-technologies.

sensors to commercial developments,

www.asmeconferences.org/

manufacturing and markets.

MicroNano08

www.biosensors-congress.elsevier.com June 8-13 May 26-30 E-MRS Symposium 2008 Strasbourg, France

eminent researchers from academia and industry to discuss and share the latest developments in nanotechnology. http://anm2008.web.ua.pt/

CIMTEC 2008, Acireale, Italy More than seven hundred technical contributions featured by the several

June 29-July 4 Science and Application of

The E-MRS 2008 Spring Meeting features

Symposia of the 3rd International

Nanotubes, Montepellier, France

17 technical symposia, an exhibit, a plenary

Conference “Smart Materials, Structures

This meeting will bring leading scientists in

session with talks by outstanding

and Systems” will cover outstanding areas

the area of nanotube science together to

researchers and a social event

of the subject from the molecular and nano

evaluate past and define future trends of this

www.emrs-strasbourg.com

scales to large complex integrated systems.

exciting field. The conference will address

www.cimtec-congress.org/2008

progress at the frontiers of fundamental as

May 28-29 Nanotechnology: Towards reducing animal testing London, UK

well as applied research and will allow June 9-13 NanoBio Europe,

participants to exchange ideas and results of their latest work in an informal atmosphere.

Due to the limitations and costs of animal

Barcelona, Spain

experimentation there is a great deal of

The major focus of the NanoBio-Europe

research being carried out on finding viable

Conference is set on medical applications

and effective alternatives. This conference

of nanobiotechnology, in particular the

July 7-9

will highlight some of the potential

characterization of cellular processes,

Nanomaterials 2008 Newcastle, UK

applications in nanotechnology in reducing

machinery and interaction to control,

NanoMaterials08 will focus on the

animal experiments while maintaining safety

manipulate or manufacture molecules or

commercialisation of nanomaterials, rather

for patients and consumers.

supramolecular assemblies to improve

than technology and theoretical benefits.

www.nano.org.uk

human health.

www.nanomaterials08.com

www.cnrs-imn.fr/NT08

www.nanobio-europe2008.com June 1-5 2008 NSTI Nanotechnology Conference and Trade Show –

July 9-11 June 10 NanoMedNet Workshop:

Seeing at the Nanoscale Berlin, Germany

Nanotech 2008, Boston USA

‘Nanomedicine: Smart Materials

The largest and most comprehensive

and Nanostructured Surface’

technical and business event in

Cambridge, UK

on nanostructural imaging, characterization,

nanotechnology world-wide with over

This workshop will bring together leading

and modification using scanning probe

30 technical & business symposia.

clinicians and medical scientists, developers

microscopy (SPM) and related techniques

www.nsti.org/Nanotech2008

of new “smart” or functionalized nano-

www.veeco.com

The annual scientific conference focusing

materials, industry experts and business June 3-5 2nd Integration &

specialists in a multidisciplinary and

Commercialization of Micro &

interactive forum to collectively examine

If you would like your event listed

and propose ways of bringing new medical

please contact the editor:

International conference and exhibition

nanomaterials effectively to the clinic.

[email protected]

focusing on state-of-the-art research and

www.nano.org.uk

Nanosystems Kowloon, Hong Kong

006

S W E N

NASA’s nano pioneer awarded Meyya Meyyappan has been awarded the 2008 Judith A Resnik Award from the IEEE (Institute of Electrical and Electronic Engineers). The award recognizes his leadership in nanotechnology, particularly his contribution to nanotubes and their applications in sensors, instrumentation and nanodevices in both aerospace and industrial applications. Meyyappan is director of the Center for Nanotechnology, NASA Ames Research Centre in California, which he helped found, in 1991. The Centre is considered the strongest nanotechnology research laboratory of any of the federal laboratories, and through his efforts, has become one for the largest and most creative in U.S. government.

Image courtesy of IEEE

Meyyappan’s research focuses on carbon nanotubes and inorganic nanowires. Among his other awards are NASA’s outstanding leadership medal and the US President’s Meritorious Award. www.ipt.arc.nasa.gov

World’s First New Carbon Nanotube Composite

Nanotube paper rolled out Physicists at Tsinghua University in China have invented a super-thin nanotube paper which has potential for use in a range of materials that boost performance of high energy density supercapacitors or remove heat from computer chips. The scientists created their ‘buckypaper’ by rolling a small steel cylinder across an array of carbon nanotubes. The resulting paper was extremely thin, yet an excellent conductor of both heat and electricity. The buckypaper is also extremely strong – demonstrated by Changhong Liu and his colleagues by folding their CNT material into an origami swan. The team also put their material to more practical use by using it to make supercapacitors—devices that can store up to 1000 times more electrical energy than standard capacitors and are often used when a large but brief surge of energy is required, such as driving the starter motor of a large engine. Supercapacitors are also being used in some prototype fuel-cell and hybrid cars to improve acceleration.

Fujitsu Laboratories Ltd have successfully combined carbon nanotubes and graphene to form a new nano-scale carbon composite. While carbon nanotubes have properties including high thermal conductivity and high current-density tolerance, graphene is known for its high electron mobility. Carbon nanostructures that combine these two materials therefore hold potential for material research and applications, such as in electronic devices, which are vulnerable to heat. The new technology was recently presented at the 34th Fulerene Nanotubes General Symposium in Japan.

The research was published in the journal Nanotechnology. www.tsinghua.edu.cn

008

www.fujitsu.com


nano

Anti-reflective films inspired by insect wings Nature has inspired Chinese researchers to produce a nanostructured anti-reflective film. The fascinating, anti-reflective properties of the cicada’s wing was used by the scientists at Peking University and the Chinese Academy of Nanotechnology and Engineering to produce the new material.

The anti-reflective property of the cicada wing, which offers camouflage to the insect, is due to a gradual refractive index profile at the interface between the wing and the air. The researchers deposited the wing in a gold form before transferring the pattern onto a film before being heated. The new

reflective material could then be peeled off using tweezers. The gold mould could be used for more than ten times, the researchers report. The research was published in Nanotechnology. http://en.pku.edu.cn/

CNT key to hydrogen storage? Researchers at Stanford University Synchrotron Radiation Laboratory have developed a new technology for storing hydrogen with carbon nanotubes, bringing us a step closer to realizing hydrogen as a source of energy. Hydrogen is the most abundant element in the university and therefore provides a valuable source of clean, renewable energy – it can be used in fuel cells to produce electricity, with the only byproduct being water. However, to date a safe, efficient and inexpensive way of storing hydrogen for use in such fuel cells has proved a challenge. For example, the energy required to compress hydrogen for storage can outweigh the benefits of energy it can generate. The new discovery involved packing hydrogen into single-walled carbon nanotubes through the formation of bonds with carbon atoms. Because the nanotubes have a large surface area, they provide a promising storage medium. Further research is needed, but there is hope for the potentials of nanotubes to contribute to future hydrogen-storing technologies. The research was published in Nano Letters. Image courtesy of Anders R Nilsson

www.stanford.edu

009

S W E N

Carbon Nanotubes Help Mend Bones Japanese scientists have discovered that carbon nanotubes could help to speed up the recovery of broken bones.

Image courtesy of John Rogers

Nanoribbons lead to bendable circuits Nanoribbons have been used to develop flexible circuit boards that could be integrated into wearable computers or biomedical devices. The nanoribbons are formed from ultrathin sheets of silicon bonded to sheets of rubber. These are the first flexibile chips to use silicon. Previously, it was believed that silicon would be too brittle to use in flexible chips

as it is quite brittle and rigid. However, the researchers led by John Rogers at the University of Illinois were able to optimize the silicon used in the nanoribbons to produce circuits that were fully foldable and stretchable.

www.uiuc.edu

When the CNTs were used in conjunction with a bone morphogenetic protein (BMP), commonly used to facilitate bone regrowth, the production of new bone material was accelerated even further.

Gripping secrets of ivy revealed

Conventional methods for treating broken bones is a lengthy process, that involves weeks of cast or splint wearing for the patient. The new technology could lead to much faster healing processes for those who experience broken bones.

Details of the new invention were published in the journal Science.

Researchers at the University of Tennessee have discovered the secret behind the ivy plant’s amazing gripping abilities – they appear to secrete nanoparticles that help them grip to surfaces. Microscopic rootlets spring out from the stems and secrete a “little yellowish matter”, as first described by Charles Darwin in 1876. Atomic force microscopy has now lifted the lid on the yellowish matter and revealed that it contains uniform particles 70nm across. The researchers believe the nanoparticles are produced inside the stem and then secreted out through the rootlets. The research team is now working out the mechanism by which the ivy produces nanoparticles and hope to work out exactly how they help the plant stick to surfaces. They will also investigate whether they could use ivy to produce other nanoparticles. www.tennessee.edu

010

CNTs placed in contact with damaged bones not only helped to regenerate bone tissue but also reduced inflammation during healing. Measurements taken as the new bone was forming revealed that the CNTs become integrated into the bone matrix and appear to act as a starting point for new bone tissue to begin to grow.

www.shinghu-u.ac.jp


nano

Hercules Beetle Inspires Intelligent Materials The Hercules Beetle is regarded to be the strongest creature in the world, capable of carrying up to 850 times its own weight, thanks to its super-strong protective shell. The shell also has other properties – the ability to change colour – which is helping scientists to design a new range of ‘intelligent materials’. The beetles’ shell changes from green to black as its surrounding atmosphere gets more humid. It is this property that interested researchers at the University of Namur in Belgium who have closely examined structures in the shell that enable it to produce these colour changes. They found that normal light interference patterns within the shell resulted in a green colour. However, when water penetrated the surface, the interference patterns were distorted and the colour appeared black.

Eco-friendly Power Paint RESEARCHERS AT SWANSEA UNIVERSITY ARE DEVELOPING A NEW, ECO-FRIENDLY TECHNOLOGY THAT THEY CLAIM COULD GENERATE AS MUCH ELECTRICITY AS 50 WIND FARMS. Dr Dave Worsley, a Reader in the Materials Research Centre at the University’s School of Engineering, is investigating ways of painting solar cells onto the flexible steel surfaces commonly used for cladding buildings. Unlike conventional solar cells, the materials being developed at Swansea are more efficient at capturing low light radiation, meaning that they are better suited to the British climate. Collaboration between Swansea University, Bangor University, University of Bath, and the Imperial College London to develop commercially viable photovoltaic materials for use within the steel industry is now underway. Paint is applied to steel when it is passed through rollers during the manufacturing process, and it is hoped that the same approach can be used to build up layers of the solar cell system. The researchers’ aim is to produce cells that can be painted onto a flexible steel surface at a rate of 30-40m2 a minute. Dr Worsley believes that the potential for the product is immense.

If we could mimic the colour-changing abilities of the shell, it could help to devise smart materials that could act as humidity sensors, in food processing plants for example, where monitoring the moisture level is of critical importance.

He said: “Corus Colours produces around 100 million square metres of steel building cladding a year. If this was treated with the photovoltaic material, and assuming a conservative 5% energy conversion rate, then we could be looking at generating 4,500 gigawatts of electricity through the solar cells annually. That’s the equivalent output of roughly 50 wind farms.”

The research was published in the New Journal of Physics.

Dr Worsley will be working closely with Corus to research practical, costefficient methods of mounting the system on steel structures, with a view to the eventual commercialisation of the product.

www.fundp.ac.be

www.swansea.ac.uk

011

Y OG L O HN C TE

Illustration by artist Pat Rawling showing the concept of a space elevator as viewed from the geostationary transfer station looking down the length of the elevator towards Earth. Picture courtesy of NASA Marshall Space Flight Center.

012


nano

Carbon Nanotubes Applications and Markets IMAGINE A CABLE, ALMOST 36 THOUSAND KILOMETRES LONG, EXTENDING FROM THE SURFACE OF THE EARTH AND CAPABLE OF TRANSPORTING PAYLOADS AND PEOPLE INTO SPACE. CARBON NANOTUBES, CONSIDERED AS THE WONDER MATERIAL OF THE 21ST CENTURY, ARE A POTENTIAL CANDIDATE MATERIAL IN THIS REVOLUTIONARY CONCEPT OF THE SPACE ELEVATOR. KSHITIJ ADITEYA SINGH EXPLORES THE RANGE OF APPLICATIONS CARBON NANOTUBES WILL OFFER AND PROVIDES A PERSPECTIVE ON THE EMERGING NANOMATERIALS MARKETPLACE.

he range of physical, chemical, optical, electronic, thermal and mechanical properties offered by carbon nanotubes has created an immense interest in this nanomaterial. Their use has been demonstrated in over 25 applications ranging from nano-scale electronics, biomedical, composites, structural, and storage, while many more are being researched.

T

Relatively mature applications – Reinforcements and interconnects Research groups and companies are actively working in applications of carbon nanotubes such as interconnects, probes in microscopes, reinforcements and polymer composites. Arrays of vertically aligned carbon nanotubes intercalated with silicon dioxide are being developed for interconnect applications. Such interconnects are ideal for use in Dynamic Random Access Memories and developing three dimensional architecture. Stanford University in collaboration with Toshiba Corporation have demonstrated a CMOS circuit using carbon nanotube as interconnects. The processor run at 1GHz speed is comparable with other CMOS chips. Tennis rackets were one of the first applications to have been reinforced with carbon nanotubes. The concept of CNT reinforcement has evolved since and, a group led by Professor Nikhil Koratkar have developed a method using carbon nanotubes for detecting and repairing cracks in nearly all types of polymers. Carbon nanotubes have also been demonstrated in light bullet proof vests and

body armor of vehicles. Researchers at the University of Sydney are studying the impact of projectiles on carbon nanotubes for use as a shield and explosion proof blankets. Pacing Applications – Displays and thermal conductors Among the applications of carbon nanotubes that use electronic and thermal conductivity are thin film transistors, flat panel displays and thermal management system. Thin film transistors made from networks of single walled carbon nanotubes at Hanyang University in Seoul have demonstrated the potential of thin film transparent electronics that can be used in e-paper, flat panel displays, opto-electronics and electronic windscreen. Nano Emissive Displays developed by Motorola as a 5 inch prototype have demonstrated the use of carbon nanotubes in display. This development is expected to change the design and fabrication of flat panel displays. Carbon nanotubes intercalated with copper create a composite material exhibiting good thermal properties that can be ideal for chip cooling. Researchers at Rensselaer Polytechnic Institute have demonstrated that carbon nanotubes can dissipate heat as effectively as copper, while being 10 times lighter and more flexible gives them added advantage. Sensors Carbon nanotube applications in sensing applications such as biosensors, chemical and pressure sensors are being investigated. NASA has demonstrated Multi-walled

»

013

Y OG L O HN C TE Carbon Nano tube array electrode functionalised with DNA, act as an ultra sensitive sensor for detecting the hybridisation of target DNAs. Surrey University has recently demonstrated chemical sensors while Rensselaer researchers have demonstrated that a small block of carbon nanotubes can be used as a highly effective pressure sensor. Drug delivery to yarns Carbon nanotubes have the potential for use across biomedical, energy, industrial adhesives and textile sectors. One of the biomedical applications of nanotube is its use as a drug delivery vehicle. Researchers at the University of London are investigating the carbon nanotube penetration of cells membranes and their interaction with different cell types. Carbon nanotubes in energy applications have been demonstrated in fuel cells as backing material for the electrodes in the membrane electrode assembly and also for the storage of hydrogen. In solar cell applications, Georgia Tech Research Institute have used carbon nanotubes as supports for arrays of photovoltaic material and also serve to connect them to the silicon wafers. University of Akron has demonstrated an adhesive application with 200 times the gripping power of gecko’s foot. It is expected to be used as a dry adhesive in microelectronics, robotics, space and other fields. Carbon nanotubes just 10-50nm in size spun in a yarn have great potential for use within textiles. Such yarns are strong, durable, flexible and retain the electrical properties of the nanotubes. Emerging application Emerging application examples of the carbon nanotubes have been observed in vibration isolation applications and are being considered in the design of NASA morphing wing of gliders. The nanomatteress developed at the Nanyang Technological University, consists of a layer of diamond-like carbon over a layer of aligned carbon nanotubes. The composite material has excellent mechanical properties and can provide vibration isolation and wear resistance applications in harsh environments. Researchers at University of California have demonstrated a nanoscale radio where the main component of the circuit consists of a single carbon nanotube. This is expected to be used in mobile phones and environment sensors. Markets The carbon nanotubes market can be viewed as a market of the material and applications. The challenges of each application vary at each stage of the development cycle and technology adoption.

014

Carbon nanotubes have three main variations based on the diameter of the tubes – single walled, double walled and multi-walled carbon nanotubes. The production capacity of individual companies remains in hundreds of tonnes. For example Nanocyl has recently demonstrated a production capacity of 100 tonnes per annum. No accurate estimate of production capacity is available though it remains in few thousands of tonnes. Poor definition of market segments and the subsequent positioning in the market has been one of the main blocks in realizing potential. An example of this is the nanocomposite market of carbon nanotubes. In relation to market understanding, acquisition of intellectual property has assumed a disproportionately more important role in positioning of products within the carbon nanotube market. In a recent paper by Raj Bawa, President of Bawa Biotechnology, significant patent thickets were reported for carbon nanotubes, mainly in the general category and electronics applications. Patent thickets and potential litigation remains a serious issue to be addressed if the markets are to realize their potential. Pricing plays an important role in successful uptake of products in the market. The main factors affecting the pricing of carbon nanotube are type of tube, diameter, purity, functionality, and quantity. For example the price of a functionalized nanotube is more than 90%-purity nanotubes, which are in turn more expensive than 60%-purity tubes. Also, the smaller the diameter of tube, the higher the price. For instance an 8nm tube is more expensive than a 30nm diameter nanotube. There is also a decrease in the price of carbon nanotubes with increasing quantities. This change is noticeable for single-walled carbon nanotubes more than multi-walled carbon nanotubes. Sharp price decreases for nanotubes have been observed around 100 gram. Analysts in 2004 had predicted the cost for a kilogram of carbon nanotube to reach $ 284 in three years. The level of scale-up required for production units by 2007, to bring prices down has not been achieved. Therefore it is

important that forecasting figures are assessed with cautious optimism. One of the causes of uncertainty in the development of the market has been the toxicity of carbon nanotubes on health and the environment. The toxicity results available are not consistent and not conclusive as yet. Governmental organizations are keen to regulate the market in order to avoid a fiasco similar to that resulting from the use of asbestos in the 1980’s. The risk governance frameworks developed by organizations such as IRGC and first certification of risk management and monitoring such as CENARIOS® seek to address some of the issues raised by the uncertainities of carbon nanotubes. These will have a positive impact on the development of the carbon nanotube market. Among other factors that will assist the development of mass market of carbon nanotube is standardization and codes of conduct. Organisations in Europe such as ISO, BSI and CEN are developing carbon nanotube characterization related standards. ASTM in the United States, along with organizations in China, Korea and Russia are also active. Codes of conduct, such as those developed by the European Commission for responsible conduct in research and Responsible NanoCode developed in UK, will have a positive bearing by defining boundaries of carbon nanotube companies and their behaviour in capital market. Researchers are constantly coming out with new ideas and applications of carbon nanotubes are expected to grow over the next decade. The development and rate of maturity of these applications will be determined by a range ofcausal factors. However not all applications will make it to market. It is none the less certain that the use of carbon nanotube as a material for multi-disciplinary engineering will continue to increase and may one day become a commodity material. Kshitij Aditeya Singh works at the Institute of Nanotechnology (UK)

S AL I ER AT M

Adapted from an image courtesy of Anthony Hoffman.

016


nano

A trick of the light? MATERIALS CAPABLE OF HARVESTING LIGHT, ABLE TO BEND WAVES AROUND CORNERS AND MAKE SOLID OBJECTS INVISIBLE ARE JUST SOME OF THE MIND-BOGGLING IDEAS THAT PHYSICISTS WORKING IN THE OBSCURE WORLD OF META-MATERIALS BELIEVE COULD ONE DAY BE REALITY. ELAINE MULCAHY SPEAKS TO PROFESSOR SIR JOHN PENDRY ABOUT THESE FASCINATING MATERIALS THAT PLAY TRICKS WITH THE LIGHT. he very origins of meta-materials defy common logic. The present generation was first discovered by Professor Pendry while he was investigating radar absorbing materials for the Marconi Company. He noticed that apart from this relatively mundane property of absorbing radar waves, the new materials could also be used to reverse electric and magnetic fields. This enabled the realisation of a brilliant theoretical suggestion made in 1967 by a Russian scientist, Victor Veselago, who had postulated that if we could find such materials, they could bend, or refract, light in the opposite direction to ordinary substances such as glass.

T

From this property all manner of extraordinary possibilities have emerged. The holy grail of meta-materials thus far has been one that bends light backwards, like an invisible mirror, obeying the mysterious and somewhat controversial concept of a negative refractive index.

»

017

S AL I ER AT M

Meta-cloak. Image courtesy of Duke University.

the electromagnetic wave we are trying to control. We don’t want the wave to “see” the individual elements, but rather to feel the collective response of many elements.”

waves in ways that were previously impossible. But finding a material with a negative refractive index was not straightforward. Any past student of physics or science will most likely have learnt about refraction. It is a well known phenomenon that occurs when light waves bend as they pass from one material to another, such as from air to glass or water. Refraction is what gives the lens in the eye the ability to bend incoming light so that it comes to focus on the retina, and what makes an object sitting in a glass of water appear closer to the surface than it actually is. The refractive index is a measure of how much a wave will change direction as it enters or leaves a material. Air has a refractive index of 1, glass has a refractive index of 1.3 and diamonds have a refractive index of 2.4. This is why they sparkle. In 1967, the Russian physicist Victor Veselago had an idea for a material with a negative refractive index. Such a material, he predicted, would make light flow backwards and would have almost magical attributes that would let it outperform any other known material. It was not until 30 years later that the possibility of realising Veselago’s dream became reality when Professor Pendry, along with scientists at Marconi Materials Technology in England, discovered that materials could be engineered to respond to electromagnetic

018

Meta-materials contain tiny circuits and wires that mimic the actions of electromagnetic responses typical of natural materials, but in reverse. Naturally, refraction occurs because the chemical makeup of the materials, air and water, for example, is different. As light, passes from air into water, electrons in the water feel the force of the incoming energy and move in response. As they soak up the energy, they disrupt the flow of the wave. Light is just one example of an electromagnetic wave, that is, one that induces an electrical and magnetic response in the material and it is this characteristic that scientists have been able to manipulate to create meta-materials. “Chemistry is not the only path to developing materials with an interesting electromagnetic response,” Pendry says. “We can also engineer electromagnetic responses by creating tiny structures that are embedded in the material and force it to behave the way we want it to.” “The most fundamental aspect of this design is that these structures are considerably smaller than the wavelength of

Electromagnetic waves, as their name suggests, generate two responses in a material. The electrical component causes electrons to move back and forth, while the magnetic component causes the electrons to go round in circles. The combined electrical and magnetic responses define a material’s refractive index and they must both be negative in order to yield a negative refractive index. This concept appears to defy some of the most basic laws of physics. Take Newton’s third law, for example – when A exerts a force on B, B exerts and equal but opposite force on A. In a material with a negative index of refraction, rather than exerting an equal but opposite force on A, B starts moving in the other direction. How is this possible? Pendry explains – Resonance is the key. “Imagine a swing oscillating at a consistent rate. This is its resonant frequency. If you push the swing periodically, in time with this swinging, it will start to arc higher and higher. However, if you try to push at a faster rate, the push will go out of phase with the motion of the swing and you will come to a point where your arms are outstretched (force A) and the swing (force B) is rushing back towards you. It is this, almost backwards, scenario that we aim to achieve in meta-materials.” In this case, repeating rows of tiny circuits consisting of wires and split-ring resonators mimic the electrical and magnetic responses of electrons in a natural material. Normally, they oscillate at a resonant

frequency, just like the swing. But, apply a wave above the resonant frequency and the response is negative – the electrons begin to oppose the incoming wave, just like the swing swinging towards the outstretched hands. These wires and split rings have become the building blocks of a wide assortment of meta-materials with various interesting properties, including the first invisibility cloak. The first demonstration of a meta-material with a negative refractive index was developed by Dr David Smith and colleagues at the University of California, San Diego in 2000. Now at Duke University, Smith has since refined his meta-material, proving in 2006 the concept of an invisibility cloak and generating widespread international excitement and media attention that we might all one day possess the ability to hide from our adversaries, just like Harry Potter! Rather than hiding a young wizard, Smith’s invisibility cloak made a slightly less magical, yet no less astounding, copper pipe invisible to microwaves. Published in Science, it was a major scientific breakthrough. Smith’s cylindrical cloak was built from layers of repeating wire and split ring circuits, designed to curve incoming microwaves around an object placed in the centre of the cylinder and then merging them back together on the other side, rendering the object invisible. A person with microwave vision would only see what was behind the cloak. Although not perfect on the first attempt (there was some shadow and grey areas),


nano



“LIGHT IS JUST ONE EXAMPLE OF AN ELECTROMAGNETIC WAVE, THAT IS, ONE THAT INDUCES AN ELECTRICAL AND MAGNETIC RESPONSE IN THE MATERIAL AND IT IS THIS CHARACTERISTIC THAT SCIENTISTS HAVE BEEN ABLE TO MANIPULATE TO CREATE META-MATERIALS.” it showed in principal that invisibility could be achieved and was not bad for a first attempt! Radio-waves, microwaves, infrared, visible light, ultra-violet, x-rays and gamma rays cover the spectrum of electromagnetic wave types, from radio-waves with the longest wavelength to gamma rays with the shortest wavelengths. Smith used microwaves in his design because of their long wavelengths, which places less demand on the fine detail required of the material circuitry. “The most obvious application of these meta-materials is radar and similar stealth applications. We may also be able to make an acoustic cloak, which some people with noisy neighbours might welcome!” Pendry says. “Static magnetic fields can also be cloaked and that may have some applications to screening the fields in an MRI set-up. The list of potential applications is significant.” Visible light sits somewhere in the middle on the electromagnetic spectrum with wavelengths in the range 400-700 nm. The elements of a meta-material capable of responding to visible light need to be orders of magnitude less than the wavelength, and therefore in the nanoscale. Smith’s cloak has proved the concept of invisibility. The next challenge is to build meta-materials containing nano-scale

Image courtesy of Keith Drake

circuitry capable of manipulating the direction of visible light. Pendry stresses, “The concept is much broader than just being able to hide something. In principle, we can literally make electromagnetic energy go where we please, though practicalities do limit this. Obvious examples are the converse of the cloak – a harvester of radiation, or guiding signals around an optical chip. I think it is these broader applications that will be most important.” Indeed, the new emerging field of metamaterial-inspired electronics, or metactronics as coined by Professor Nader Engheta, was recently developed and described by him in Science. Engheta, who heads research into optical nanocircuits at the University of Pennsylvania, has provided an insight into future electronics which could see significant miniaturisation of circuits in parallel with an increase in storage capacity as we switch to nano-scale circuitry capable of exploiting light rather than electrons. Engheta’s circuits are created from a collection of nanoparticles of different materials and properties aligned next to one another. The different nanoparticle elements represent elements typical of a conventional electronic circuit – capacitor, resistor, inductor. By exploiting the optical properties of metamaterials, the nano-circuit elements shape and tailor optical fields in the circuit. “The blueprint for optical nanocircuitry that links the fields of metamaterials, optics and electronics has been laid down,” Engheta says. “The coming years will be an exciting time as we build on this knowledge to create new technologies and devices in this evolving field.”

Illustration showing what happens in normal refraction.

Illustration showing what happens in negative refraction. Images courtesy of Martin Wegener

Professor Sir John Pendry is Chair in Theoretical Solid State Physics at Imperial College London

019

S AL I ER AT M

020


nano

Smart Yarns Advances in carbon nanotube technologies are driving the generation of a new class of materials that cross the biomedical, textiles and electronics industries. FUTURE APPLICATIONS COULD USE NERVE CELLS GROWN ON NANOTUBE YARNS AS INTERCONNECTS FOR THOUGHT-BASED CONTROL OF ARTIFICIAL LIMBS. MEANWHILE, YARNS MADE FROM NANOTUBE FIBRES COULD BE INCORPORATED INTO CLOTHING, OR EVEN ARTIFICIAL MUSCLES, TO MAKE THEM SMARTER, STRONGER AND MORE POWERFUL. PROFESSOR RAY BAUGHMAN EXPLAINS SOME EMERGING TECHNOLOGIES THAT ARE LEADING TO A NEW GENERATION OF SMART MATERIALS. The science of spinning goes way back. Our Stone Age ancestors twisted tufts of animal hair with their hands to make strong pieces of string. Today, much more sophisticated equipment is used to spin cotton and wool to create yarns for a range of textiles from clothing to car seats, but the basic technology remains the same. Individual short fibres are twisted together to create long, high strength yarn. This yarn can in turn be twisted together to create even stronger yarns. Baughman and his colleagues at the University of Texas in Dallas have downsized such twist-based spinning to the nanoscale by replacing conventional yarn fibres with a thousand times thinner carbon nanotubes. In 2006, they wove the first nanotube textile from these yarns – it was the size of a finger nail and super strong. Since then, they have progressed research into the development of nanotube sheets and yarns that could be used as scaffolds

for growing nerve cells as well as for application in a range of smart textiles, sensors and electronic components. Nanotube Forests But where do the nanotubes for spinning these yarns come from? “Carbon nanotube sheets and yarns are made by drawing nanotubes from the side of a ‘nanotube forest’,” Baughman explains. “Carbon nanotubes in a nanotube forest are arranged like bamboo trees in a bamboo forest. However, these nanotubes are skinny, over 30,000 times longer than their diameter. This means that there is about three billion kilometres of nanotubes in each kilogram of yarn. The challenge is to assemble these extremely long lengths of nanotubes into yarn and sheets at industrially useful rates. This seems feasible since we have already demonstrated sheet draw from nanotube forests at 30 metre per minute. In a continuous process, fast-growing forests of carbon nanotubes could be grown on one end of a moving belt and stripped off at the other end to create our sheets and yarns. ” There has been much progress in the creation of these nanotube forests over the past number of years from groups working around the world. The Japanese team of Kenji Hata and Sumio Iijima at Japan’s National Institute of Advanced Industrial Science and Technology (AIST), for example, have grown forests of individual nanotubes just 1-5 nm in diameter that are more than two millimetres tall. A research group at the University of Cincinnati have grown even taller nanotube forests, which reach centimetre lengths.



Sheets of strength Baughman and his colleagues were able to draw sheets of nanotubes from the sides of such forests using an adhesive strip, which can even be the sticky edge of a Post-it note. Metre long sheets of nanotube fibres up to 5 cm wide and just 50 nm thick were formed and displayed enormous strength – a sheet could hold a droplet of water, which was 50,000 times more massive than the sheet area where it sat, without breaking. On a per weight basis, the strength of these nanotube sheets is higher than the strongest steel plate! As well as super strength, the nanotube sheets are transparent and able to conduct electricity, which makes them potentially very useful as electrodes for flat panel displays and solar cells. Indeed, Baughman’s colleagues Anvar Zakhidov and John Ferraris recently started a company called Solarno that focuses on using carbon nanotube sheets in combination with other nanotechnologybased materials for solar energy harvesting. Scaffolds for building on Baughman’s collaborators Pedro Galvan and Mario Romero of Scottish Rite Hospital in Dallas successfully grew human skin fibroblasts and animal brain cells on carbon nanotube sheet scaffolds. High growth rates to provide organized structures provide advantages compared to conventional glass and plastic scaffolds. The researchers think the sheets were so effective because of the giant surface area they present to the cells, which may be more similar to the natural internal environment of the body than glass or plastic can provide.

“THE SCIENCE OF SPINNING GOES WAY BACK. OUR STONE AGE ANCESTORS TWISTED TUFTS OF ANIMAL HAIR WITH THEIR HANDS TO MAKE STRONG PIECES OF STRING. TODAY, MUCH MORE SOPHISTICATED EQUIPMENT IS USED TO SPIN COTTON AND WOOL TO CREATE YARNS FOR A RANGE OF TEXTILES FROM CLOTHING TO CAR SEATS” 021

S AL I ER AT M Nerve cells, or neurons, are extremely sensitive to their environment and can be quite difficult to grow. However, Baughman and his team have managed to successfully grow neurons on CNT sheets. In fact, the neurons appeared to thrive on the sheets, extending axons outwards from the cell body. Baughman says, “The highly supportive nature of carbon nanotube sheets for directed cellular growth and migration could have applications in areas such as wound healing and nerve regeneration.” “The ability to grow nerve cells on CNT sheets has great potential for electrically interfacing neurons,” Baughman says. “We are now investigating whether we can record and stimulate neurons over the longterm on these CNT sheets. If successful, nanotube yarns or sheets could be wonderful scaffolds for repairing nerve injuries and even the creation of highresolution brain-machine interfaces.” Spinning yarns As well as drawing sheets from nanotube forests, Baughman and his team have developed technology to spin nanotube fibres to create yarns that have unlimited lengths. Nanotubes about 10 nm in diameter are simultaneously drawn from the forest and twisted to generate strong yarns having a thousand times larger diameter. These yarns are flexible, tough and highly

022

conducting. Individual yarns can in turn be spun together to generate 2-, 4-, 10-ply yarns, and so on.

textiles that contain metal wires to provide heating, electrostatic discharge protection and microwave absorption, for example.”

The cross section of one of these yarns, which is ten times smaller in diameter than a human hair, contains about 100,000 individual nanotube fibres – a thousand times greater number than for commercial wool or cotton yarns having much larger diameter.

Muscle power Creating artificial muscles using nano-yarns is another area of applications research at the Nanotech Institute. When electrically powered, these nanotube muscles can generate over a hundred times the force of a natural muscle.

Their strength, toughness and conducting properties mean these yarns have potential in a vast array of technologies, from cold electron emitters for intense lamps and miniature x-ray sources to electronic textiles, bullet proof vests, artificial muscles, and composites for making lighter aircraft. As textiles used for smart clothing, for example, they could be used to monitor heart rate and vital signs of astronauts travelling to outer space or athletes seeking to enhance performance.

Other artificial muscles developed by the NanoTech Institute are instead powered by highly energetic fuels. These fuel powered muscles, which can use ether carbon nanotubes or special nanotech-based metal wires, help solve one of the problems with electrically powering artificial muscles – the amount of energy that can be stored in a battery is too low for long operation of highly athletic advanced robots.

“Replacing metal wires in electronic textiles with these nanotube yarns could provide important new functionalities, such as the ability to actuate as an artificial muscle and to store energy as a super-capacitor or battery,” Baughman says. “Because the yarns have extremely small diameters, they could eliminate the uncomfortable rigidity sometimes found in

The NanoTech Institutes’ fuel powered muscles, which use either alcohol or hydrogen for fuel, are 100 times stronger than natural muscles, able to do 100 times greater work per cycle and produce, at reduced strengths, larger contractions than natural muscles. Among other possibilities, these muscles could enable fuel-powered artificial limbs, “smart skins” and morphing structures for air and marine vehicles, autonomous robots having very long


nano



CREATING ARTIFICIAL MUSCLES USING NANOYARNS IS ANOTHER AREA OF APPLICATIONS RESEARCH AT THE NANOTECH INSTITUTE. WHEN ELECTRICALLY POWERED, THESE NANOTUBE MUSCLES CAN GENERATE OVER A HUNDRED TIMES THE FORCE OF A NATURAL MUSCLE. mission capabilities and smart sensors that detect and self-actuate to change the environment. Driving forward These and other related applications of carbon nanotube yarns and sheets are grouped within the Institutes NanoEnergetics program, where the novel electronic, optical, and mechanical properties of carbon nanotubes are used for energy harvesting, energy storage, and energy conversion. Synergism exists, so that advances in one application enable advances in others. For example, Anvar Zakhidov, associate director of the NanoTech Institute, leads key projects on solar energy harvesting and high efficiency light sources that use oppositely directed processes that are intimately related. Likewise, some of the artificial muscles can be driven mechanically, so that mechanical energy is converted to electrical energy. Also, related electrochemical cells are being used for storing electrical energy,

harvesting solar energy or waste thermal energy, and for the operation of artificial muscles. In some instances, a single electrode is multifunctional – fuel powered artificial muscle electrodes act as fuel cell electrodes to convert chemical energy to electrical energy, as supercapacitor electrodes to store this electrical energy as injected charge, and as artificial muscles to use changes in injected charge to provide actuation. “While none of these applications of our nanotube yarns and sheets have yet reached the market place, these are exciting times for research on carbon nanotubes. We and others around the world are making rapid advances that might lead to game-changing products”, says Baughman. Professor Ray Baughman is the Director of the Alan G. MacDiarmid NanoTech Institute at the University of Texas in Dallas

023

LD OR W

Nanotechnology in Japan JAPAN HAS LONG BEEN RECOGNISED AS A WORLD LEADER AND KEY PLAYER IN GLOBAL ADVANCES IN SCIENCE AND TECHNOLOGY AND RECENT INVESTMENT AND PROGRESS IS ESTABLISHING THE COUNTRY’S PLACE IN THE GLOBAL NANOTECHNOLOGY ARENA. Japan’s position as a leader in technology over the past two decades have come in large part from a realisation by the government during the 1990s of a need to excel in the sciences in order to set Japan apart.

“However, even in the deteriorating financial circumstances, governmental R&D expenditure increased. Now onto the third Basic Plan, the Japanese economy has recovered and we are looking toward a more sustainable growth path.”

As a result, the Science and Technology Basic Law was enacted which led to the implementation of a series of “Basic Plans” to focus R&D spending and scientific achievement to specific areas deemed of national and international importance.

Indeed, Japanese spending on research and development today is one of the greatest in the world, consistently exceeding that of many other developed nations by millions of pounds and believed to account for a quarter of global R&D spend.

The first and second Basic Plans were successfully implemented from 1996-2000 and 2001-2005 respectively. The third Basic Plan, which commenced in 2006, will run until 2010 and see investment estimated at about 25 trillion Yen (160 billion euro). “The first and second basic plans were formulated and carried out during a period of prolonged economic stagnation in Japan following the collapse of the bubble economy,” Dr Edward Wright, First Secretary of Science and Innovation at the British Embassy in Tokyo says.

024

But, Japan does feel the pressure of its convictions on the global scale. “Being a world leader means expectations are high,” Wright says. “Japan, a country possessing excellent Science and Technology is expected, more than ever before, to contribute to human society through the resolution of the difficult challenges we face by using its national S&T capability.” “Many efforts have been made to resolve global-scale problems concerning

population, the environment, food, energy and resources, but difficult challenges still remain such as sustainable development of human society. Science and Technology achievements will need to be great if we are to avoid passing these problems to the next generation.” The Basic Plan is based on three core ideas: To create human wisdom, maximise national potential, and protect the nation’s health and security. Four priority research areas – life sciences, information and telecommunications, environmental sciences and nano technology/materials – are the priority focus for research investment and all are geared towards achieving the three core ideas of human wisdom, national potential and protection. Secondary prioritised areas are energy, manufacturing technology, infrastructure and space/oceans. Nanotech The Government has poured significant amounts of money into nanotechnology – 86.5bn (500m Euro) investment is planned for 2008. The private sector has also made large commitments to the field. The Ministry of Economy, Trade and Industry (METI) estimates private sector investment of more than Y40 billion on nanoscience R&D in 2003 and there are currently around 500 nanotechnology related companies in


nano

A nano-flower: Aligned single-walled carbon nanotubes synthesized by water-assisted CVD on patterned catalysts. Image courtesy of Kenji Hata.



JAPAN’S POSITION AS A LEADER IN TECHNOLOGY OVER THE PAST TWO DECADES HAVE COME IN LARGE PART FROM A REALISATION BY THE GOVERNMENT DURING THE 1990S OF A NEED TO EXCEL IN THE SCIENCES IN ORDER TO SET JAPAN APART.

Japan. An estimate from the Mitsubishi Research Institute and Nikkei Shimbun puts the size of the market for Japanese nano-related technologies in 2005 at Y8.5 trillion and expected to increase to over Y19 trillion by 2010. Going back to the key research themes, a significant proportion of Japan’s nanotechnology research efforts take on an

environmental agenda, such as reducing the weight of transportation equipment and the creation of energy saving buildings equipped with light controlling glass and humidity-controlling walls. Japan already prides itself on leading the world in energy. In solar power generation, for example, Japan achieved the world’s highest power conversion efficiency and

developed the technology for mass production, while the amount of solar power generated in Japan accounts for 50 per cent of the global total. During the period of the third basic plan, the environment relating to Science and Technology is expected to change remarkably at home and abroad and much effort has been focussed on advancing research in sustainable and environmental sciences. The Ministry of Education, Culture, Sports, Science and Technology (MEXT) has led policy development on the strategic promotion and development of

»

025

nanotechnology and materials. The ministry’s efforts also include support for human resource development and multidisciplinary R&D. Four prioritized areas identified are: Information technology: Quantum information and communications for highspeed and ultra-large-capacity information processing (quantum information and communications, quantum computation, quantum memory/relay chips), molecular/bio/spin electronics based on novel materials and functions (single molecular integrated devices, single-spin memory chips and sensor devices), nextgeneration electronics for high-speed and large-capacity information processing (terabit memory chips, ultra-highspeed/highly integrated LSIs, quantum dot optical devices and power devices) Life Sciences: Bionanotechnology for realizing tailor-made diagnosis/therapy (cell therapy, bionanomaterials, bionanomachines and bio-inspirednanodevices/systems), molecular/bio/ spin electronics Environment: Environment/energy nanomaterials for realizing higher efficiency and new functions (nanostructure-controlled materials for fuel cells, eco-energy conversion nanomaterials and nanocatalysts) Basic technologies: Fabrication technology for developing novel nanostructure-controlled materials to realize new functions and significant improvements in material property (sub-nano-tailored materials, nano-soft machines, programmed self-organization), nanomeasurement/analysis/fabrication (three-dimensional visualization technology of nanostructures and nanoscale properties, nanoelectromechanical systems (NEMSs), single-molecular manipulators), modeling/simulation of nanomaterials and first-principal calculations/molecular dynamics calculations. Recommendations by MEXT also include the strategic enhancement of facilities, such as the establishment of a large-scale R&D centre and measurement and analysis technologies and facilities that are becoming more and more important for understanding nano-scale design and materials.




nano

THE NEW IDEA OF “MINIMAL MANUFACTURING” IS A KEY STRATEGY AREA AT AIST. THE CONCEPT DESCRIBES TECHNOLOGICAL SYSTEMS THAT ARE CAPABLE OF CREATING PRODUCTS WITH MAXIMUM FUNCTIONS FROM MINIMAL RESOURCE INPUTS USING MINIMAL ENERGY IN THE MANUFACTURING PROCESS, AND WITH A MINIMAL END-OF-LIFE EFFECT ON THE ENVIRONMENT. The establishment of research networks that span disciplines and a concentrated effort to strengthen human resources in nanomaterials at universities and international exchange programmes to encourage a new generation of experts in these emerging areas of science are also of key importance along with collaboration across industry, government and universities. “Academia has proven to be successful at generating the seed technologies. It is imperative that industry takes the initiative to enable this research to flourish to practical applications,” Wright says. Society In Japan, it is important that science and technology return more than economic benefits. People also expect contribution to society, which is changing remarkably due to the rapidly aging population and declining birth rate, the resolution of safety issues relating to public concerns about large scale natural disasters and security issues, and the resolution of global-scale problems concerning populations and the environment. The current basic plan is based on encouraging more public information and support and an emphasis on fostering human resources and competitive research environments. “For the development of a competitive environment in S&T, it is important for people engaged in S&T to generate creative ideas, have an opportunity to compete and receive fair judgement,” Wright says. The potential societal implications and risks associated with nanotechnology are not lost in any of the Japanese government’s investment strategies. While nanotechnology is recognised as a field that will raise new studies and new industries and is expected to perform a grand contribution for the development of society

and the economy as well as improving living conditions, the potential negative impact on the human body, environment and society are also considered. Japan’s National Institute of Advanced Industrial Science and Technology (AIST) published the first roadmap for the risk assessment of nanomaterials, providing a schedule for the analysis and exposure, followed by risk assessment. The Nanotechnology Business Creation Initiative (NBCI), a consortium of 320 private companies, has also established a working group for societal impacts and standardisation of nanocarbon materials, particularly carbon nanotubes. AIST Much of Japan’s research advances emerge from the National Institute, launched in 2001, AIST is an amalgamation of 15 research institutes employing about 2500 researchers and more than 3000 visiting academics, post-doctoral fellows and students, covering all of Japan’s priority R&D areas. The new idea of “minimal manufacturing” is a key strategy area at AIST. The concept describes technological systems that are capable of creating products with maximum functions from minimal resource inputs using minimal energy in the manufacturing process, and with a minimal end-of-life effect on the environment. A number of research Institutes have been established at AIST to drive forward research in many areas of nanotechnology, such as sustainable development and global warming countermeasures, as well as the more traditional nanotech fields of Advanced manufacturing and carbon materials among others. Significant advances that have already emerged from AIST include technologies for growing nano-forests, active targeting drug-delivery nanoparticles and development of the world’s highest resolution magnetic force microscope.

027

W IE V R TE IN

Nobel conversation OTTILIA SAXL INTERVIEWS SIR HARRY KROTO, WHO RECEIVED THE NOBEL PRIZE FOR CHEMISTRY, IN 1996, ALONG WITH ROBERT CURL AND RICHARD SMALLEY FOR THE DISCOVERY OF CARBON C60, AN ENTIRELY NEW FORM OF CARBON WITH MANY INTRIGUING PROPERTIES. SIR HARRY IS CONVINCED THAT THE WORLD OF CIVIL ENGINEERING WILL CHANGE AS DEFECT-FREE STRUCTURES ARE CREATED ONCE LONG LENGTHS OF CARBON NANOTUBES HAVING A CONSISTENT DIAMETER CAN BE ROUTINELY SYNTHESIZED.. part from his research and other interests, Sir Harry has been active in enabling leading scientists to communicate with the public through the Vega Trust, and has more recently set up a new website, GeoSet, which offers a forum for young scientists to share their ideas and research, using video and powerpoint.

A

OS: What inspired you to become a chemist? HK: Well, I was good at chemistry, but what I really wanted to be was a Wimbledon champion. I was good at art and graphics as well, but in the ‘50’s there was no real

future in these as a career. My father, who had been a refugee, ran a small family business, and was keen for me to join him. But both my chemistry teacher and my art teacher were very supportive of me continuing my studies, and it was my chemistry teacher, Harry Heaney, who encouraged me to go to Sheffield University. So I went to University and read chemistry (science was certainly one of the better options for getting a job!) where I became fascinated by quantum mechanics and spectroscopy. I also found that University was a way to continue my education and interests! – I played tennis for Sheffield,

In spite of winning the Nobel Prize for Chemistry as one of the discoverers of carbon C60, buckminster fullerene, Sir Harry Kroto bemoans missing out on a Wimbledon title, and still views the world of graphic design as where his real interests and talents lie!

028

got involved in athletics and worked on the student magazine. I did so many things there that I wanted to stay on, and did so by taking a PhD in Spectroscopy. Essentially, University for me was a place I could do all the things I was interested in, so I gave it a try for 5 years. A post-doc opportunity then opened up in Canada, so I moved there, and then I wanted to live in the States, so I went to work for a time in Bell Labs. After a while I wanted to get back to the UK, and came to Sussex. Coming home was certainly a shock – particularly a financial shock – my salary dropped from $14,000 a year to £1,400! But we survived. OS: What were the highlights along the path that led to the discovery of Carbon C60?


nano



I WAS GOOD AT CHEMISTRY, BUT WHAT I REALLY WANTED TO BE WAS A WIMBLEDON CHAMPION. I WAS GOOD AT ART AND GRAPHICS AS WELL, BUT IN THE ‘50’S THERE WAS NO REAL FUTURE IN THESE AS A CAREER New forms of the element carbon - called fullerenes - in which the atoms are arranged in closed shells were discovered in 1985 by Robert F. Curl, Harold W. Kroto and Richard E. Smalley. Fullerenes are formed when vaporised carbon

HK: One of the highlights was getting a job! I enjoyed teaching, but my big success at Sussex was pioneering studies on molecules with carbon-phosphorus multiple bonds that led to the now prolific field of phosphor alkene / alkyne chemistry. Another highlight was my work on carbon chain molecules undertaken with David Walton – polyamine spectroscopists have always had a close relationship with radio astronomers! - from which the start of my role in the discovery of C60 can be directly traced. Looking at microwave spectroscopy in the lab, and measuring absorbed / emitted radio waves had many similarities to working on interstellar space where unusual carbon molecules can be found, coming from carbon stars. This led eventually to the discovery of carbon C60 (in collaboration with Curl and Smalley).

condenses in an atmosphere of inert gas. Curl, Kroto and Smalley were able produce clusters with 60 carbon atoms and clusters with 70. Clusters of 60 carbon atoms, C60, were the most abundant with a high stability. It was suggested that C60 could be a "truncated icosahedron cage", a polyhedron with 20 hexagonal (6-angled) surfaces and 12 pentagonal (5-angled) surfaces. The pattern of a European football has exactly this structure, as does the geodetic dome designed by the American architect R. Buckminster Fuller for the 1967 Montreal World Exhibition. The researchers named the newly-discovered structure buckminsterfullerene after him. Taken from the Press Release, 1996 Nobel Prize for Chemistry

OS: Where do you think the discovery of carbon C60 is leading? HK: The discovery of carbon C60 opened up our understanding of carbonaceous network structures that hadn’t been forseen. All materials have problems based on defects, for example a diamond will crack along a defect; or a tree can be cut by sawing into a defect. The discovery of C60 led to a

recognition of the strength of caged structures. If you could make these cages, the defects of many structures could be overcome. For example, a box of loose straws is weak, they will have no strength. Glue them together and the box becomes incredibly strong. Defects do not propagate in this kind of structure, and it solves a long-standing problem of how to design out defects.

029

W IE V R TE IN

Sir Harry Kroto, Dept Chemistry, Florida State University Sir Harry obtained his BSc and PhD at Sheffield University. His early research focused on the creation of new molecules with multiple bonds; and in the late 1970’s his work led him to discover that long linear chain molecules existed in interstellar space and within stars. In the late 1980’s lab experiments at Rice University in Houston, were able to simulate the chemical reactions taking place in red giant stars, revealing that C60 could self-assemble. This changed the whole perspective on the nanoscale behaviour of graphite in particular, and sheet materials in general. Sir Harry was knighted in 1996 and received the Nobel Prize in the same year for the discovery of C60, a new form of carbon, sharing it with Richard Smalley and Robert Curl. The sticking point is that we cannot control the synthesis of carbon nanotubes. We are not going to have any revolutionary breakthrough in creating ultra strong materials unless we are able to routinely control the diameter and chirality of the » tubes. Carbon nanotubes would have incredible properties if we could make them of a consistent diameter and in large quantities, but we just don’t know how to yet. Although we can produce a good yield, consistency of production is still in its infancy. What we need is a ‘box’ of CNT ‘straws’ – at least 1015 of them, 1m long and 1nm in diameter for defect-free applications. There are already niche applications of CNTs but we need to develop those that are in competition with mainstream technologies. We can’t overcome the existing technologies that are in place at present, but a revolution in civil engineering will be possible once we can control the production of CNTs in a consistent manner. OS: Sir Harry, if we can talk about the Vega Trust you formed. What is the Trust about, and what are its goals? HK: The Vega Trust (www.vega.org.uk) was founded originally to create a platform for

030

scientists to communicate directly with the public. I wanted to create a set of programmes where great scientists could communicate their views directly to the public on issues of importance. This has been achieved. 150 programmes have now been made, with the help of the OU; and 55 of these have been shown on the BBC. The Vega site is now a tremendous archive of the scientific thinkers of the day and I want to see it continuing to be added to. The Vega Trust programmes include extraordinary interviews, lectures and panel debates and discussions with world-class scientists of the last 50 years. It even contains rare footage of four lectures given



by Richard Feynman in New Zealand, courtesy of the University of Auckland.

We have now set up another, less costly (!) site, GeoSet, www.geoset.info which will be as meaningful for science and education as Wikipedia and YouTube are for their communities of interest. It contains video and downloadable powerpoint slides, put there by bright young scientists who are communicating their ideas in order to educate the wider world about their research, while also providing role models for other youngsters. It is a parallel initiative, and I want other universities to set up a similar opportunity for their students to contribute to GeoSet. My hope is that in 10 years, everything on modern science education will be in there. OS: So, what about future plans? HK: I would like to do one more good piece of scientific work in Florida, and then get back to art and graphics!

THE VEGA TRUST PROGRAMMES INCLUDE EXTRAORDINARY INTERVIEWS, LECTURES AND PANEL DEBATES AND DISCUSSIONS WITH WORLD-CLASS SCIENTISTS OF THE LAST 50 YEARS. IT EVEN CONTAINS RARE FOOTAGE OF FOUR LECTURES GIVEN BY RICHARD FEYNMAN IN NEW ZEALAND, COURTESY OF THE UNIVERSITY OF AUCKLAND.

H RC A SE RE

Plumbing carbon nanotubes CARBON NANOTUBES HAVE THE POTENTIAL TO RADICALLY CHANGE ELECTRONICS AND ARE AMONG THE MOST LIKELY CANDIDATES FOR MINIATURIZING ELECTRONIC COMPONENTS BEYOND THE MICRO-SCALE. BUT BEFORE NANOTUBE CIRCUITS CAN BE BUILT, SCIENTISTS FIRST NEED TO PERFECT THE TECHNOLOGY FOR ATTACHING AND WELDING NANOTUBES TOGETHER. SCIENTISTS AT JAPAN’S NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY DESCRIBE A NOVEL “PLUMBING” TECHNIQUE THAT CONNECTS CARBON NANOTUBES TOGETHER LIKE WATER PIPES. he possibility of connecting carbon nanotubes together like water pipes has enormous potential for both creating longer tubes and adding Tjunctions and changes in direction, like we see in many plumbing systems. Such an advance would provide us with the technology to start building a new group of bottom-up engineered nanostructures and devices with a range of applications in electronics, such as field-effect transistors and current lead-wires.

T

Research led by Dr Kazu Suenaga and Dr Chuanhong Jin recently reported in Nature Nanotechnology on a new method of plumbing carbon nanotubes, both of the same and different diameters, together.

032

Connecting nanotubes of different diameters together has proved to be extremely difficult and so the researchers first explored mechanisms for connecting nanotubes of the same diameter. Using a transmission electron microscope to watch the nano-structures in action, the scientists first split a carbon nanotube by bridging it across two electrodes and gradually increasing the current between them. As the current increased, the section of nanotube between the two electrodes narrowed until eventually, at approximately 12µA, it split into two daughter nanotubes, each with a closed-cap head. Jin and his colleagues then set out to reattach the nanotubes to create a single tube

again. The two capped ends were moved close together and again the voltage and current were gradually increased. At certain threshold values, the two daughter nanotubes reconnected in a process so quick and sudden that the researchers are still unsure about how it worked. But, it has been repeatable. “The whole process, from breaking of the original carbon nanotube to joining the two daughter nanotubes, can be repeated many times over. So far, we have successfully repeated it up to seven times on the same nanotube,” Jin said. “A systematic investigation of a large number of carbon nanotubes has further reinforced these findings. All 13 attempts at


nano



“THIS SIMPLE METHOD OF PLUMBING CARBON NANOTUBES, LIKE WATER PIPES, WILL ENABLE US TO BUILD LONGER AND MULTIBRANCHED NANOTUBES WITH SERIAL JUNCTIONS MADE BY REPEATED JOINING,” JIN SAID.

joining ‘cap to cap’ carbon nanotubes were successful when they stemmed from the same tube.” The ability to split and re-connect carbon nanotubes is important in terms of scientific discovery but may lack practical application when it comes to building bottom-up electronic devices. In this regard, connection of nanotubes from different parent tubes and at different locations along the tubes (such as cap to side-wall) may be far more relevant – and has proven far more difficult. “It seems to be intrinsically difficult to join two carbon nanotubes with completely different diameters,” Jin said. “Using the techniques described above, all 16 attempts at joining nanotubes with different diameters failed, as did repeated attempts to form a Y-type junction in a ‘capto-wall’ orientation.” In fact, rather than joining together, carbon nanotubes of different diameters tend to shy away from each other. Deformities appear on the surface, they start to shrink and detach and appear to do everything they can not to join. Jin believes this is down to differences in the way the atoms are organised, or the chirality, in different nanotubes. Nanotubes from the same mother tube have the same chirality and so re-connecting them is more straightforward. But attempts to force nanotubes of different chiralities together do not work because of a mismatch at the atomic level. What the scientists needed was the equivalent of a plumbing fixture to smooth

the transition from one tube to the next. Tungsten provided this solution. Tungsten has long been known to help carbon atoms organise themselves into ordered structures. Carbon nanotubes typically consist of a repeating lattice of hexagonal carbon cells. The cap of the nanotube, however, consists of pentagonshaped cells that need to adjust in order for the two tubes to join. Jin and his colleagues found that when they placed a tungsten particle between two carbon nanotubes of different diameters, it caused the surrounding atoms to re-align and essentially create a common layer. Moving the tungsten particle back and forth helped to strengthen the bond between the two nanotubes. “Eventually a new carbon nanotube is fabricated and a seamless connection between the two tubes with completely different diameters is achieved,” Jin said. “Not only does this mechanism work for nanotubes of different diameters, but it can also be used to connect nanotubes of the same diameter. The major benefit is that it requires much lower temperatures than connection without the tungsten particle. Also, tungsten is not the only particle that could be used – nickel, iron and doped boron may also yield similar results.” The possibility of connecting carbon nanotubes together in this manner opens a range of possibilities for bottom-up engineering of nanotube structures, from simply increasing their aspect ratio to making integrated carbon nanotube devices.



“SUCH TECHNOLOGIES HAVE POSITIVE IMPLICATIONS FOR DEVICE APPLICATIONS OF CARBON NANOTUBES SUCH AS FIELDEFFECT TRANSISTORS.” “This simple method of plumbing carbon nanotubes, like water pipes, will enable us to build longer and multi-branched nanotubes with serial junctions made by repeated joining,” Jin said. “Such technologies have positive implications for device applications of carbon nanotubes such as field-effect transistors.” Kazu Suenaga added, “We believe the present work is a tour-de-force of nanotechnology and demonstrates the possibilities for the ultimate bottom-up process to fabricate nanodevices. “In this way, connecting a semiconducting nanotube and a metallic nanotube to build a nano-diode is now definitely achievable. Also, the potential to manipulate individual quantum objects provides great promise for realizing exotic physical properties, and is therefore intriguing in the field of electronics and optics.” Drs Chuanhong Jin and Kazu Suenaga are researchers at the National Institute of Advanced Industrial Science and Technology in Japan. Further reading Chuanhong Jin, Kazu Suenaga, Sumio Ijima (2008). Plumbing carbon nanotubes. Nature Nanotechnology, Vol. 3 January 2008.

033

E QU I N CH E T

Ellipsometry and Polarimetry Towards understanding and predicting the properties of nanoparticles and nanocomposites

034


nano RESEARCH HAS SHOWN THE VERSATILE NATURE OF ELLIPSOMETRY AS A FUNCTIONAL, NANOSCALE SENSITIVE AND NON-DESTRUCTIVE TECHNIQUE THAT IS PAVING AN EFFECTIVE WAY FOR ENGINEERING A RANGE OF NEW NANOSTRUCTURES WITH TAILORED, FUNCTIONAL OPTICAL PROPERTIES AND COLOUR FOR OPTICS, PHOTONICS, AND BIOMEDICAL APPLICATIONS RANGING FROM THERAPEUTICS TO DIAGNOSTICS. oday’s ellipsometry is becoming popular in a widening field of applications because of the increasing miniaturization of integrated circuits, breakthroughs in knowledge of biological macromolecules deriving from DNA and protein surface research, materials physics design of thin film multilayer surfaces, composite and smart materials and materials engineering at the nanoscale.

T

Characterization of nanoparticles and nanomaterials is absolutely fundamental to science and technology success in all those fields, and to address this, a world-class consortium of experts has been brought together in the European Coordination Action NanoCharM that will provide scientists and companies with the leadingedge tools they need to succeed in this globally important and competitive market.

A different kind, but even more dramatic example concerns the colour of simple metals. A bulk metal typically reflects more or less all of the impinging light, as long as its surface is smooth. We can all see this effect when we look in the mirror. Typically metals are thought of as either conductors (in electronics) or reflectors (in optics). So, at first glance, the use of metallic structures to transmit light signals seems impractical, because metals are known for their high optical losses. Metal nanostructures are a different story: they may absorb only certain wavelengths of light, depending on the composition, size and shape. Naturally, the metal nanoparticles can then reflect back only the light that is not absorbed, and so can appear in many dramatically different colours, depending on their nanostructure size. Because of their fascinating optical properties, metallic nanostructures with a characteristic size of few tens-hundreds of nanometers are now attracting a growing interest.

Metal Nanostructures – The Colour of Size In contrast to simple bulk materials, the optical properties of nanostructures depend very much on their size and shape, as well as the composition of the material in which they are found. Of especial importance, for instance, is the so-called quantum size effect in semiconductor nanostructures that may result in light being emitted when an electrical current is passed through the semiconductor.

From an electromagnetic point of view, metals can be considered as plasmas, comprising fixed, positive ion cores and free conduction electrons. Recent interest has been focused on the exploitation of the synchronized oscillations of the conduction electrons that are displaced when visible light strikes some metal nanoparticles, such as gold, silver, copper, indium, gallium, palladium, and so on. This gives rise to extra absorption at characteristic wavelengths, called surface plasmon resonance (SPR), and, consequently, to size and shape-dependent colours that are characteristic of each material.

In addition to the type of semiconductor material, the size of the nanostructure is responsible for the colour (or wavelength) of the emitted light. This is because electrons in the material at the border of the nanostructure experience changes in energy, and as a consequence, the wavelength of the light they emit.

This exciting field has become known as “Plasmonics”. Plasmonic surface resonance can dramatically enhance the local electro-magnetic (EM) field by concentrating EM energy into nanoscale volumes, and lead to a plethora of intriguing physical phenomena and applications.

Here, NanoCharm provide an insightful look at metal nanostructures and the impact of ellipsometry on this exciting new field.

035

E QU I N CH E T

Stained glass windows are an example of materials that use nanoparticles to add colour.

Examples are many and varied. Metal nanoparticles can be used in optoelectronics to enhance light emitters (lasers) and photodetectors; they can be used for special effects in paints and cosmetics; as tracers in pharmaceuticals; in spectacular self-cleaning surface coatings; and as functionalised (covered with suitable coatings and bio-molecules) metal nanoparticles in ultrasensitive chemical and biological sensors; in high throughput cancer screening and also in colorimetric chemical and photochemical reactions Bringing ancient technologies into the 21st century The colours obtained from some metal nanoparticles were known to medieval artisans unconscious of the fact that they were early nanotechnologists, who mixed gold and copper nanoparticles into molten glass to create composite materials that absorbed and reflected light in a way that produced a rich ruby colour. In fact, those effects have been used since middle age times for producing glowing colours, particularly for ‘stained’ glass in church

036

windows. Another famous example of the use of metal nanoparticles is the Lycurgus Cup (British Museum; 4th Century A.D.) containing gold nanoparticles of typically 5nm – 60 nm in size, whose colour changes from greenish to red when it is illuminated from inside because of the plasmonic excitation of the gold nanoparticles within the glass. Nowadays, metal nanostructures are created based on the rational design of size and shape, and exploit various metals, not just gold and silver but also gallium, indium, copper and palladium. Thanks to advances in modern nanotechnology and the science behind it, engineers can now make carefully controlled nanostructures of many kinds of metals in the quality, quantity, and yield required for the systematic investigation of their peculiar properties. This process is aided by advances in hardware and software that have improved optical diagnostic capabilities to the point where fast, real-time nanoparticle-formation processes can now be monitored. Among the various optical techniques, the high the speed of ellipsometry, and its sensitivity to sub-monolayer changes in thin films, makes

it a powerful method for non-invasive and non-destructive investigations of nanostructure dynamics in real time. Shining a light on the mysteries of the nanoverse Microscopy techniques are used to image nanostructures, however “seeing” nanoparticles is no longer enough we need to know how they obtain their properties and what they can be used for. This requires an understanding of how the novel optical phenomena relate to the nano-dimensionality of the nanostructure. If a nanocomposite consists of metal nano-islands of similar size and shape for example, the size and shape of these nanostructures may dominate the optical response. However, while optical properties of simple bulk materials are mostly well understood, the basis of optical behavior of different nanostructures remain a great challenge. Controlling the optical behavior of nanoparticles is of key importance for exploiting their properties in several


nano emerging technologies. For example, selective optical filters, novel solar cells configurations, bio-sensors and nanoparticle tracers for cancer detection are among the many applications that use the optical properties of gold nanoparticles that derive from surface plasmon resonances which in turn depend strongly on the anisotropy of the particle shape. Despite the great importance of the optical response of nanoparticles, it is generally not easily characterized and practically never able to be controlled. This situation is not due to the negligence of scientists but rather to the intrinsic difficulty of accurately characterizing the properties of the nanoparticles, and the limited number of ways known for controlling and tailoring them. From “seeing” nanoparticles to defining the optical and physical properties of nanoscale materials, ellipsometry techniques represent a step forward in metal nanoparticle characterization without contacting or damaging the sample. Ellipsometry and polarimetry Ellipsometry and polarimetry are optical, non-destructive and non-invasive diagnostic techniques that allow the interplay of nanostructures – properties – functionalities to be addressed with a sensitivity down to Angstrom resolution. In ellipsometry and polarimetry, a light beam of known polarization impinges on the surface of a material. When reflected it changes its polarization state, allowing the optical properties to be extracted (namely the refractive index and absorption of the sample) in a quantitative way. Ellipsometry as an ‘interactive diagnostic’ controlling light with light The ellipsometry technique is highly attractive for under-standing both the optical and electrical properties, as well as the dimensionality of metal nanostructures, since it can be used as an interactive diagnostic. Light impinging on a sample can light up optical phenomena such as the plasmon resonance of the sample, and simultaneously detect and analyse the phenomena themselves. The power of the technique comes from the fact that it is very sensitive to thin layers and small optical index variations; from one single measurement on a substrate, various details can be inferred including the refractive index, absorption, thickness of thin layers and interfaces, composition and nano-dimensionality of the material.

The surface plasmon resonance of metal nanostructures depends on nanoparticles size and shape, but primarily on its refractive index and on the refractive index of the surrounding media. The dielectric function (refractive index) is the principle behind ellipsometry, making it suitable and sensitive to detect and tailor the optical response of metal nanostructures.

The above figure shows an example of 50nm gold nanoparticles assembled to mimic a raspberry on a silicon surface, whose corresponding ellipsometric spectra shows the SPR absorption peak at a wavelength of 620nm, corresponding to a ruby colour. It is worth noting that the ellipsometry analysis simultaneously gives the optical response, the SPR characteristics - which are determinant for addressing the nanoparticles’ functionality, and also the thickness or height of the nanoparticle assembly, which is 91±1Å as determined by ellipsometry, as compared to 92Å measured by atomic force microscopy (the latter images geometry only, without addressing the optical and functional properties). The peak wavelength (620 nm) of the plasmon absorption band is larger than that of the same gold nanoparticles in solution (520 nm-green). This red-shift resulted from the aggregation of nanoparticles on the silicon substrate. Another important advantage of ellipsometry is that nanoparticles can be measured without any constraint on substrate (except that it must reflect light). This differentiates ellipsometry from the more conventional reflectance and absorption spectroscopies which are limited by the use of transparent substrates such as glass and quartz to support metal nanostructures. How “nano” is the nanostructure and what optical properties does it have? Ellipsometry can give a direct answer by acquiring the spectra of the nanoparticles’ absorption. The size of the nanoparticles can be inferred by the position of the SPR peak, while the amplitude of the peak gives information on the density and inter-coupling of nanoparticles. (Figure 6). Therefore, this is an extremely versatile tool for determining the size of nanoparticles in real time.

Ellipsometric probing/exploring all changes: tailoring of metal nano-structure colour for great sensitivity in bio-interfacing and colorimetric sensing Ellipsometry and polarimetry techniques open up the possibility of studying the kinetics of nanostructure formation and the environmental parameters affecting the growth of metal nanostructures, as well as their phase transformation. It is a valuable method for investigating the dynamic changes in metallic nanostructures caused by an external stimulus, such as variations in temperature and pressure, the presence and variation of electrical and magnetic fields, and the addition of analytes (gases and biomolecules) during chemical sensing and bio-sensing. The ellipsometric sensitivity and SPR response to “dressing” the metal nanoparticles with coatings and biomolecules can yield data on the thickness of the layer covering the nanoparticles and the surface of nanoparticles engineered to target specific gases (chemical sensing) or specific proteins and cells, such as antibodies. This versatile nature of ellipsometry is proving it to be a promising, functional nanoscale technique that may play an important role in the generation of a new range of highly specified nanostructures for optics, photonics and biomedical applications. *NanoCharM (Multifunctional Nanomaterials Characterization Exploiting Ellipso-Metry and Polarimetry). A Concerted Action of the EU’s Framework Programme 7. To learn more about the project and the consortium partners, please visit www.nanocharm.org Dr Maria Losurdo, Institute of Inorganic Methodologies and Plasmas, IMIP-CNR, University of Bari, Italy, co-ordinator of the FP7 NanoCharM* project and Norbert Esser, ISAS (Institute for Analytical Sciences), Dortmund and Berlin, Germany For further reading: H.G. Tompkins, E.A Irene: Handbook of Ellipsometry (William Andrew, Applied Science Piublisher, 2006) H.G. Tompkins, W.A.McGahan: Spectroscopic Ellipsometry and Reflectometry (Wiley, New York 1999) Y. Xia, N.J. Halas, MRS Bullettin 30, 328 (2005) Shape-Controlled Synthesis and Surface Plasmonic Properties of Metallic Nanostructures G. Mie: Ann. Phys. 25, 377 (1908): The Mie theory W.A.Weyl: Coloured Glasses (Dawson’s of Pall Mall, London 1959)

037

L CA I ED M

Nanomedicine: Keeping things in perspective MANY SCIENTISTS CLAIM THAT NANOTECHNOLOGY IS A RATHER ARTIFICIAL TERM AND THAT IT IS ONLY “…WHAT WE HAVE BEEN DOING FOR AGES” …WHETHER IN PHYSICS, CHEMISTRY OR BIOLOGY. ON THE OTHER HAND, THERE IS A HUGE HYPE AND FUSS ABOUT “NANOTECHNOLOGY” AND THE APPEARANCE OF THE “NANO“ PREFIX ON A WIDE RANGE OF CONSUMER PRODUCTS FROM SKIN CREAM TO PERSONAL ELECTRONIC DEVICES AND AUTOMOTIVE PRODUCTS TO STONE CLEANERS. SO WHY HAS “NANO” BECOME SUCH A BUZZWORD FOR SOME, WHILST RAISING SCEPTICISM IN OTHERS? FOR CLUES WE PERHAPS NEED TO LOOK BACK TO THE EARLY DAYS OF NANOTECHNOLOGY. RICHARD MOORE EXPLORERS THE ORIGINS OF NANOTECHNOLOGY

While the term “nanotechnology” (one nanometre (nm) equals one billionth of a metre and the nanoscale is generally considered to be the region 1 to 100 nm) was first coined by Norio Taniguchi in his 1974 paper entitled “On the Basic Concept of “Nano-Technology” it first came to the attention of the public in the mid 1980s when its first major proponent, Eric Drexler, laid out an ambitious futuristic scenario in his book, Engines of Creation. This predicted nanoscale “universal assemblers” capable of creating“…almost anything that the laws of nature allow to exist”. The book was a hit and inspired the start of a huge amount of research at the nanoscale. At the same time the idea was picked up by the popular media, creating an immediate public interest in the new field of “nanotechnology” which has remained, for better or worse, until the present.

038

Futuristic visions of nanomedicine do not only come from science fiction. Robert Freitas Jr., Senior Research Fellow at the Institute for Molecular Manufacturing in Palo Alto, California and author of the Nanomedicine series3 is a leading proponent of the concept of medical nanorobotics. He published the first detailed prospective technical design study for a medical nanodevice, the “respirocyte,” in 19984 and continues an exploration of the future possibilities for medical nanorobotics in the Nanomedicine series. While, in the long term, this technology may become feasible, science is currently at a much less complex stage of implementing medical solutions at the nanoscale. Yet, the idea of the medical robot busily repairing cells in the bloodstream remains firmly in the public imagination and is an image regularly repeated in the popular media.

Striking a balance Currently, medicine at the nanoscale offers the prospect of highly effective new drug delivery systems, greatly improved imaging, biosensing and diagnosis, new structures and materials for use in regenerative medicine (where the body is encouraged to regenerate tissues itself), whole new generations of highly miniaturized medical devices, and exciting new treatments for cancer, diabetes and other, sometimes previously untreatable, diseases. This prospect is reflected in the huge amount of EU research funding in the “priority streams” of health and nanotechnology, some €6.1 billion and €3.5 billion respectively, a large proportion of which is directed towards research in nanomedicine. This development is likely to be a gradual and incremental process across a number


nano of converging disciplines, perhaps only culminating in the much longer term in smart, multifunctional, microscopic devices, built up from nanoscale components, of the type foreseen by Freitas and others, manufactured by “bottom-up” molecular assembly. Perhaps, however, this rapid progress has in part been fuelled by the visions of Robert Freitas and other pioneers, through the inspiration of new generations of students, scientists and medical researchers. While it is not wise to raise public expectations or fears by some of the more outlandish ideas of science fiction, it is perhaps valid to postulate on where the increased ability to engineer at the nanoscale may take society. Defining nanotechnology Returning to the original question… is nanotechnology something new or merely an extension of existing science and technology? It is probably both. Certainly, the ability to investigate nanoscale phenomena can be seen as the natural and logical extension to existing sciences. Chemistry and some branches of physics have always been concerned with nanoscale interactions, as has molecular biology, and practitioners of those sciences can justifiably claim to have always “done nanotechnology.” But nanotechnology is defined by many of its practitioners as being more than that. It is defined in the British Standards Institution’s PAS 71 as the “design, characterization, production and application of structures, devices and systems by controlling shape and size at the nanoscale” and it is multidisciplinary and product-focused by its very nature. Until fairly recently it was impossible to consistently apply the necessary tools and control at the nanoscale to manufacture more than simple materials and structures, and certainly not the range of products in current development and envisioned for the future. A number of medical products incorporating nanotechnology-based materials have already appeared on the market such as • suture needles incorporating stainless steel nanocrystals • nanodiamond-coated surgical blades



• superparamagnetic iron oxide (SPIO) nanoparticles for magnetic resonance imaging • wound dressings incorporating nanocrystalline silver particles Other more advanced nanomedical products currently in development include • nanoporous drug-eluting vascular stent coatings • nanobubbles for ultrasonic imaging • nanoshells for photothermal ablation cancer treatment • magnetic nanoparticles for cancer treatment • drug delivery systems based on a wide range of nanoparticles and other nanostructures • nanotechnology-based biosensors • lab-on-a-chip devices with nanoscale features • nanofeatured tissue-engineering scaffolds • multifunctional, targeted “theranostic” nanoparticles capable of being imaged and activated at the chosen disease site This list of examples is by no means exhaustive and there are many other clinical areas and applications where nanotechnology is beginning to have a major impact. Nanomedicine, in particular, is characterized by a strong convergence of different disciplines. The application of nanoscience and nanotechnology to imaging, diagnostics, regenerative medicine, the design of advanced medical materials and novel drug delivery systems typically involves interfaces and interactions between biology and chemistry, physics, materials science and other fields. This is also driven by the ever greater understanding of biochemical processes and the sometimes novel ways that nanomaterials react with the human body. Understanding and communicating nanotechnology risks While such research progresses it is important not to forget that there may, in addition to benefits, be potential new risks arising from nanoscale properties of materials, and that how these risks are addressed and communicated can affect the public’s perception. In the past, some

MEDIA REPORTS FREQUENTLY IGNORE SCIENTIFIC FACT AND DWELL ON PHANTOM RISKS, OR OTHERWISE MISINTERPRET THEM BADLY. YET, MOST PEOPLE ARE ABLE TO TAKE COMPLEX DECISIONS ABOUT RISKS IF THEY ARE SUFFICIENTLY AND PROPERLY INFORMED AND PERCEIVE A BENEFIT THAT SUBSTANTIALLY OUTWEIGHS ANY RISKS.

new technology or scientific issues have been badly mishandled in the way that information about risks has been communicated to the public. Notable examples include BSE (bovine spongiform encephalopathy or “mad cow disease”), genetically modified organisms (GMOs), contaminated blood, and the notion of a nanotechnology “grey goo” (the latter involving fears arising from a science fiction story further amplified by press misunderstanding of the science). Such incidents have left public trust in scientists, certain industries and government institutions at a rather low ebb. Media reports frequently ignore scientific fact and dwell on phantom risks, or otherwise misinterpret them badly. Yet, most people are able to take complex decisions about risks if they are sufficiently and properly informed and perceive a benefit that substantially outweighs any risks. As the science becomes more complex and “invisible” it is therefore necessary to put a proportionately greater effort into risk research of novel nanomaterials and nanotechnology-based products and applications, and into communicating the results with the public. This needs to include informing them about both benefits and risks, short and long-term, as well as the measures that have been taken to reduce risks, and engaging them in the governance processes that will undoubtedly impact on their lives in the not-so-distant future. Article adapted from one by the same author that previously appeared in Medical Device Technology, 2008. Richard Moore is Manager of Nanomedicine and Life Sciences at the Institute of Nanotechnology. Further Reading N. Taniguchi, On the Basic Concept of “Nano-Technology,” Proc. Intl. Conf. Prod. Eng., Tokyo, Part II, Japan Society of Precision Engineering (1974). Eric K. Drexler, Engines of Creation: The Coming Era of Nanotechnology, Anchor Books, New York, New York, USA (1986) Robert A. Freitas Jr., Nanomedicine (series), Landes Bioscience (also available online at www.nanomedicine.com) Robert A. Freitas Jr., “Exploratory Design in Medical Nanotechnology: A Mechanical Artificial Red Cell,” Artificial Cells, Blood Substitutes, and Immobil. Biotech, 26, 411–430 (1998) Publicly Available Specification (PAS) 71:2005, Vocabulary, Nanoparticles, British Standards Institution (2005)

039

T EN M M O C

How the current economic crisis will effect nanotechnology development THE CURRENT ECONOMIC SLOWDOWN, TRIGGERED BY THE SUBPRIME MORTGAGE COLLAPSE IN THE US IS LIKELY TO HAVE FAR-REACHING IMPLICATIONS. PYTHAGORAS PETRATOS DESCRIBES THE CURRENT CRISIS AND OUTLINES THE EFFECTS IT IS LIKELY TO HAVE ON THE DEVELOPMENT OF NANOTECHNOLOGY.

A year has passed since the first pessimistic voices about a potential US subprime mortgage crisis were heard. As it has now proved, this was realism rather than pessimism. Recently, at the World Economic Forum at Davos there was concern of either an economic slowdown or recession. The opinions however differed on the severity of the crisis. The subprime crisis may have revealed a deeper problem on the management of

040

credit risk. It has also triggered a liquidity crisis that has negative effects for the whole economy. And it is not only the US economy. Globalization has increased association among various economies. Therefore a slowdown, or even worse a recession, is likely to have a harmful impact on other national economies, industries and technologies. Analyzing the current economic crisis is complicated because it depends on numerous factors. The aim is to identify some important parameters that might have a significant impact on nanotechnology development. As a starting point, we look to the lending market as this is where

subprime mortgages belong. The main characteristic of the subprime market is that it lends to borrowers with poor credit history. Rather than the traditional home owner repaying the bank relationship, subprime mortgages are financed with the issuance of mortgage bonds. There are two crucial features presented above: The bond market, which is in a sense an extension of the lending market, and credit history. When the price of houses started to decline, the mortgage bond market failed to fulfill expectations. The results were significant losses - investment groups and banks lost many billions of


nano



DURING A CRISIS INVESTORS USUALLY TRY TO AVOID RISKY ASSETS WITH THE PURPOSE OF REDUCING RISK IN THEIR PORTFOLIOS. BANKS, MUTUAL AND HEDGE FUNDS PLUMMETED AS US, EUROPEAN AND ASIAN STOCKS FELL, AFTER PROFITS CONCERNS BY TECHNOLOGY FIRMS THAT A SLOWING US ECONOMY COULD HURT CORPORATE EARNINGS GLOBALLY. dollars. The result today is that banks and other lenders are cutting back on how much credit they will make available. This poses substantial problems for nanotechnology companies. Firstly, it might now be much harder to raise capital and even more difficult to sell new products. Raising capital is important for high tech firms, such as nanotechnology companies, since it is likely that numerous resources are essential before a company becomes profitable. Secondly, a major factor is credit history. Banks and lenders in general use historical evidence in order to view not only the current credit worthiness, but also to forecast the risk associated with future ability to repay debts and loans. This is a fundamental problem for nanotechnology companies. The sector of nanotechnology is relatively new and while promising, it is still an immature technology. And, the evolution of nanotechnology is perhaps slower since it has not yet experienced a “boom” as in biotechnology or the internet industries. A natural consequence is that there is a lack of financial data for nanotechnology companies. Of course there are sophisticated techniques in finance, using for example appropriate comparables, but this increases uncertainty in credit rating. Credit risk increases too, which enhances the difficulty of borrowing. Particularly in the current situation, now that the restrictions on lending have been toughened, a good credit rating is necessary. On the other hand, modern financial markets provide numerous alternatives. Venture capital is probably the most common in the high tech industries. Therefore nanotechnology companies can find a source of funds for further development. The disadvantage however is that Venture Capital firms or other types of private equity as business angels require an increased Rate Of Return on investments in order to match the associated large risks. In addition to the traditional sizeable amount of

risk in high tech firms, current caveats such as limited liquidity in the financial markets and credit risk mentioned above, augment the rate of borrowing money, and accordingly the rate of return. These rates might be prohibitive for some nanotechnology entrepreneurs, who naturally want a good share of returns to be rewarded for their risky effort too. During a crisis investors usually try to avoid risky assets with the purpose of reducing risk in their portfolios. Banks, mutual and hedge funds plummeted as US, European and Asian stocks fell, after profits concerns by technology firms that a slowing US economy could hurt corporate earnings globally. The warnings by technology companies reveal that in current conditions it is likely that reduction in their profits will occur. Thus, the technology industry transmits caution and investors will probably turn to safer, less risky investments. An example is the preference to gold and other precious metals which significantly increased their demand and their market price. The role of government in the development of nanotechnology has proved critical. Many national governments and authorities such as the European Union have supported the promotion of nanotechnology by providing funds. The resources are parts of budgets, local, national or federal. In a period of economic crisis it is likely that some government economic resources will be channeled to solve it. The US House of Representatives, for example, have

approved $146 billion in tax cuts while there are actions for additional subprime rescue plans. This could be translated to budget cuts in other fields. And taking into account that technology and nanotechnology is risky, some of its money could be allocated in other activities. This analysis is rather simplistic since only few aspects are presented. The examination of economic factors and their association and impact to each other is much more complicated; but at least it has briefly highlighted the influence that the current economic crisis might have on the development of nanotechnology. This can be summarized in the phrase of Simon Walker, the chief executive of British Venture Capital Association (BVCA) that “clouds are gathering. This is not going to be an easy year for the economy or for private equity. The economic environment is becoming much tougher”. It seems the economic slowdown that the private equity and venture capital industry prepares for is likely to be a contagious effect of the broader financial crisis. Consequently this contagion can influence the nanotechnology industry. Pythagoras Petratos is a Researcher at Queen Mary, University of London Information was sourced from the following to complete this article: BBC News The US sub-prime crisis in graphics. Wednesday, November 21, 2007. Betts P. et al,. Subprime Blows. Financial Times, Friday, November 16, 2007, Asia Edition 1. British Venture Capital Association. (2008). Private equity predicts economic slowdown at http://www.bvca.co.uk/ Waki N. Corporate profit concerns drive global shares lower. Thursday, February 7, 2008. Reuters. Wolf R. House moves quickly to pass stimulus bill. Monday, January 29, 2008. USA Today

041

advertorial

UAlbany NanoCollege Addresses Unique Nanotechnology Challenges

Amid the approaching limits of conventional computer chip scaling, the world’s leading university-research funding agency for nanoelectronics and related technologies has developed a world-class consortium designed to enable new advances in nanoelectronics that are critical to the production of smaller, faster and cheaper computer nanochips The Semiconductor Research Corporation (SRC) in February designated the College of Nanoscale Science and Engineering (CNSE) of the University at Albany-SUNY as the headquarters and lead of the New York Center for Advanced Interconnect Science and Technology (NY CAIST), which engages the best and brightest from more than a dozen leading research universities who are collaborating to ensure continuation of the furious pace of innovation within the nanoelectronics industry. NY CAIST is just the latest program playing an integral role in New York State’s pioneering strategy to further establish an R&D-manufacturing ecosystem already well underway at the UAlbany NanoCollege. With a current net asset base of $4.2 billion located within 450,000 square feet of stateof-the-art facilities at CNSE’s Albany NanoTech complex, including 65,000 square feet of Class 1 capable, 300mm wafer cleanrooms, the UAlbany NanoCollege is home to over 2,000 scientists, researchers, engineers and technicians from many of the world’s leading nanoelectronics companies, such as IBM, AMD, SEMATECH, Tokyo Electron, Applied Materials, ASML, Micron, Ebara, Toshiba, Freescale, Vistec Lithography and Atotech, among many others. The high-tech workforce on-site will increase to more than 2,500 by mid-2009, courtesy of an expansion project that will swell the size of CNSE’s Albany NanoTech to more than 800,000 square feet and its Class 1 capable 300mm wafer cleanroom space to 80,000 square feet. Combined with the emergence of nanofabrication infrastructure on the 300mm wafer format, the convergence of nanotechnology with electronics, photonics, bioelectronics, microsystems and wireless technologies is rapidly approaching. This convergence will accelerate growth in a broad array of industries by enabling the development of pervasive tether-free computing. However, unlocking the enormous market opportunities in such diverse sectors as energy, biohealth and security will remain elusive until a common integration platform and a coherent roadmap for achieving interoperability is established.

The development of nanolithography technology, such as Extreme Ultra Violet (EUV) and direct-write electron-beam, 3-D wafer-scale system-ina-package integration, and nanostructured materials’ processes such as atomic layer deposition (ALD) and silicon-on-insulator (SOI), are some of the key technology drivers under development for integrating nanotechnology in logic and memory devices at CNSE’s Albany NanoTech, in partnership with more than 250 global industry partners. With the development of the industry supply chain for nanolithography, 3-D waferscale packaging and ALD processing, industry compliant approaches for integrating logic, memory, sensors, wireless and power will soon be available, enabling pervasive tether-free computing in diverse market segments over the next three to five years. The increasing cost and related risk associated with atomic scale manufacturing requires a closer coupling between research, development and manufacturing. A new generation of institutions executing dynamic cross-industry, cross-disciplinary models is emerging, led by CNSE, responding to the unique challenges and opportunities created by nanotechnology. These institutions are establishing a new paradigm for cutting-edge research, education and technology deployment that offers industry and government a highly leveraged return on its investment in projects, programs and centers. New York State is leading the world by providing over $700 million in governmental support, combined with over $3.5 billion in corporate investments at CNSE, creating a Quick-Turn-Around-Time (QTAT) 200mm and 300mm wafer pilot-prototyping and workforce training capability at CNSE. New York’s investments provide the critical “missing link” for commercialization by reducing the risk, cost and time to market of nanotechnology-enabled devices for our industry partners. Albany’s unique IPoriented Integration Lab Model, which supports partnerships between the NanoCollege and small, medium and large-sized companies in verticallyintegrated teams, enables the successful integration of multifunctional devices for low-cost, field-robust, tether-free computing applications. Michael Fancher Assistant VP for Economic Outreach & Business Development Associate Professor of Nanoeconomics UAlbany College of Nanoscale Science & Engineering


nano

NanoArt EACH MONTH WE BRING YOU OUR CHOICE OF NANO ART. PLEASE WRITE TO US AT THE ADDRESS AT THE FRONT OF THE MAGAZINE TO SUBMIT YOUR PICTURES. The image featured in this issue – Nano Bouquet was created by Dr Ghim Wei and Professor Mark E Welland at the Nanoscience Centre, University of Cambridge. The image shows nanowires of Silicon Carbide that have been guided into forming individual flower-like structures through controlling catalytic growth at the nanoscale. Image courtesy of Dr Ghim Wei Ho and Prof Mark E Welland, Nanoscience Centre, University of Cambridge.

043

Specialists in Electron Beam Lithography At Kelvin Nanotechnology Ltd (KNT) we provide

Kelvin Nanotechnology provides a wide range of R&D and prototyping services for the semiconductor, optoelectronic, bioelectronic and nanoelectronic market places.

nanofabrication solutions

Our Core Competencies include:

to industry and academia

• Electron Beam Lithography

delivered through our

• Molecular Beam Epitaxy

state of the art James

• Nanofabrication services

Watt Nanofabrication

• Technology prototyping and proof of concept

Centre in Glasgow.

• Product development We specialise in high resolution, large area, multilevel electron beam lithography for applications such as transistor gate writing, imprint masks, optical elements, photonic crystals, nanotextured surfaces and many more. Kelvin Nanotechnology has over twenty years experience in electron beam lithography and nanofabrication. Electron beam lithography provides a route to rapid and flexible nano-patterning for a vast range of applications. Single or multi-level patterns can be written onto almost any type of substrate then transferred by etching or depositing any number of metals, insulators, biocompatible materials, optical or electronic layers. As the proliferation of nanotechnology into new application spaces gathers pace, KNT is constantly expanding and developing our industrially facing processes and technology. We are keen to learn about client applications and technical challenges and how we might use our expertise and experience to satisfy their micro and nanofabrication needs.

Kelvin Nanotechnology Ltd T: +44 (0)141 330 4869 E: [email protected] For more information or to find out how we can help you, please contact us at www.kelvinnanotechnology.com

With the help of Kelvin Nanotechnology Ltd, companies can use nanotechnology to develop new products and services and benefit from an established Nanotechnology Centre of Excellence. KNT has set up a strategic partnership with incubation and business support provider Photonix Ltd to provide companies, research institutes and funders access to the advanced capabilities and expertise that exist within both. This partnership enables KNT to deliver a clear route from idea through technology and company incubation to production.