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The absence of a universally accepted strict definition of nanotechnology has allowed the research emphasis to broaden, encompassing many areas of work that have traditionally been referred to as chemistry or biology. Thus, the first major characteristic of activity grouped under this section is that contemporary R&D cuts across a wide range of industrial sectors.
‘Smart’ Packaging for Food
In some cases, major markets are fairly well defined. The food industry serves as a good example here, where there are significant drivers at work. To illustrate, ‘smart’ wrappings for the food industry (that indicate freshness or otherwise) are close to the market. By 2006, beer packaging is anticipated by industry to use the highest weight of nano-strengthened material, at 3 million lbs., followed by meats and carbonated soft drinks. By 2011, meanwhile, the total figure might reach almost 100 million lbs.
Catalysts for Fuel and Materials
In other cases, important applications are identified but the eventual market impacts are more difficult to predict. For example, nanotechnology is anticipated to yield significant advances in catalyst technology. If these potential applications are realized then the impact on society will be dramatic, as catalysts, arguably the most important technology in our modern society, enable the production of a wide range of materials and fuels.
Nanotechnology Progress Measured by Increase in R&D Publishing
A second characteristic of current work in this area is that the kinds of materials and processes being developed are necessarily ‘technology pushed’: urged on by the potential impacts of nanotechnology, the R&D community is achieving rapid advances in basic science and technology. This level of scientific interest is gauged by Compano and Hullman who examine the world-wide number of publications in nanotechnology in the Science Citation Index (SCI) database. They conclude that for the period between 1989 and 1998 the average annual growth rate in the number of publications is an ‘impressive’ 27%.
Countries Who Are Leading the Way
This rise in interest is not confined to a small number of central repositories, however. Instead, research is spread across more than 30 countries that have developed nanotechnology activities and plans. In this way, Compano and Hullman also examine the distribution of this interest. Based upon their findings, the most active is the US, with roughly one-quarter of all publications, followed by Japan, China, France, the UK and Russia. These countries alone account for 70% of the world’s scientific papers on nanotechnology. In particular, for China and Russia the shares are outstanding in comparison with their general presence in the SCI database and show the significance of nanoscience in their research systems.
The Market for Novel Materials (‘Nanomaterials’)
The third major characteristic of activity grouped under this section concerns that fact that nanotechnology is primarily about making things. For this reason, most of the existing focus of R&D centres on ‘nanomaterials’: novel materials whose molecular structure has been engineered at the nanometre scale. Indeed, Saxl states that ‘material science and technology is fundamental to a majority of the applications of nanotechnology.’ Thus, many of the materials that follow (Table 1) involve either bulk production of conventional compounds that are much smaller (and hence exhibit different properties) or new nanomaterials, such as fullerenes and nanotubes. The market’s range of nanomaterials are considerable. Indeed, it has been estimated that, aided by nanotechnology, novel materials and processes can be expected to have a market impact of over US$340 billion within a decade.
Table 1. Summary of the major nanomaterials currently in research and development and their potential applications.
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Clusters of atoms
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Quantum wells
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Ultra-thin layers - usually a few nanometres thick - of semiconductor material (the well) grown between barrier material by modern crystal growth technologies. The barrier materials trap electrons in the ultra-thin layers, thus producing a number of useful properties. These properties have led, for example, to the development of highly efficient laser devices.
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CD players have made use of quantum well lasers for several years. More recent developments promise to make these nanodevices commonplace in low-cost telecommunications and optics.
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Current - 5 years
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Quantum dots
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Fluorescent nanoparticles that are invisible until ‘lit up’ by ultraviolet light. They can be made to exhibit a range of colours, depending on their composition.
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Telecommunications, optics.
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7–8 years.
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Polymers
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Organic-based materials that emit light when an electric current is applied to them and vice versa.
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Computing, energy conversion.
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?
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Grains that are less than 100nm in size
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Nanocapsules
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Buckminsterfuller-enes are the most well known example. Discovered in 1985, these C60 particles are 1nm in width.
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Many applications envisaged, e.g. nanoparticulate dry lubricant for engineering.
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Current - 2 years.
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Catalytic nanoparticles
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In the range of 1–10 nm, such materials were in existence long before it was realised that they belonged to the realms of nanotechnology. However, recent developments are enabling a given mass of catalyst to present more surface area for reaction, hence improving its performance. Following this, such catalytic nanoparticles can often be regenerated for further use.
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Wide range of applications, including materials, fuel and food production, health and agriculture.
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Current - ?
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Fibres that are less than 100nm in diameter
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Carbon nanotubes
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Two types of nanotube exist: the single-wall carbon nanotubes, the so-called ‘Buckytubes’, and multilayer carbon nanotubes. Both consist of graphitic carbon and typically have an internal diameter of 5 nm and an external diameter of 10 nm. Described as the ‘most important material in nanotechnology today’, it has been calculated that nanotube-based material has the potential to become 50–100 times stronger than steel at one sixth of the weight.
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Many applications are envisaged: space and aircraft manufacture, automobiles and construction. Multi-layered carbon nanotubes are already available in practical commercial quantities. Buckytubes some way off large-scale commercial production
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Current - 5 years.
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Films that are less than 100nm in thickness
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Self-assembling monolayers (SAMs)
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Organic or inorganic substances spontaneously form a layer one molecule thick on a surface. Additional layers can be added, leading to laminates where each layer is just one molecule in depth.
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A wide range of applications, based on properties ranging from being chemically active to being wear resistant.
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2–5 years.
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Nano-particulate coatings.
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Coating technology is now being strongly influenced by nanotechnology. E.g. metallic stainless steel coatings sprayed using nanocrystalline powders have been shown to possess increased hardness when compared with conventional coatings.
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Sensors, reaction beds, liquid crystal manufacturing, molecular wires, lubrication and protective layers, anti-corrosion coatings, tougher and harder cutting tools.
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5–15 years.
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Nanostructured materials
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Nano-composites
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Composites are combinations of metals, ceramics, polymers and biological materials that allow multi- functional behaviour. When materials are introduced that exist at the nanolevel, nanocomposites are formed, and the material’s properties - e.g. hardness, transparency, porosity - are altered.
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A number of applications, particularly where purity and electrical conductivity characteristics are important, such as in microelectronics. Commercial exploitation of these materials is currently small, the most ubiquitous of these being carbon black, which finds widespread industrial application, particularly in vehicle tyres.
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Current - 2 years.
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Textiles
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Incorporation of nanoparticles and capsules into clothing leading to increased lightness and durability, and ‘smart’ fabrics (that change their physical properties according to the wearer’s clothing).
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Military, lifestyle.
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3-5 years.
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The Importance of Nanotubes
Nanotubes provide a good example of how basic R&D can take off into full-scale market application in one specific area. Described as ‘the most important material in nanotechnology today’, nanotubes are a new material with remarkable tensile strength. Indeed, taking current technical barriers into account, nanotube-based material is anticipated to become 50–100 times stronger than steel at one-sixth of the weight. This development would dwarf the improvements that carbon fibres brought to composites.
Could Nanotubes Start a New Industrial Revolution?
Harry Kroto, who was awarded the Nobel Prize for the discovery of C60 Buckminsterfullerene, states that such advances will take ‘a long, long time’ to achieve, the first applications of nanotubes being in composite development. However, if such technologies do eventually arrive, the results will be awesome: they will ‘be equivalent to James Watt’s invention of the condenser’, a development that kick-started the industrial revolution.
What is the Space Elevator?
The concept of the space elevator serves as a good illustration of the kind of visionary thinking that recent nanotube development has inspired. The idea of a ‘lift to the stars’ is not itself particularly new: a Russian engineer, Yuri Artutanov, penned the idea of an elevator - perhaps powered by a laser that could quietly transport payloads and people to a space platform - as early as 1960. However, such ideas have always been hampered by the lack of material strength necessary to make the cable attachment. The nanotube may be the key to overcoming this longstanding obstacle, making the space elevator a reality in just 15 years time. This development, though, will rely on the successful incorporation of nanotubes into fibres or ribbons and successfully avoiding various atmospheric dangers, such as lightning strikes, micrometeors, and human-made space debris.
Space and Aircraft Industries will be First to Use Nanotubes
The market impetus behind such developments, then, is clear: the conventional space industry is anticipated as the first major customer, followed by aircraft manufacturers. However, as production costs drop (currently US$20–1200/g), nanotubes are expected to find widespread application in such large industries as automobiles and construction. In fact, it is possible to conceive of a market in any area of industry that will benefit from lighter and stronger materials.
The Worldwide Race to Manufacture Nanotubes
It is expectations such as these that are currently fuelling the race to develop techniques of nanotube mass-production in economic quantities. The ETC Group states that there are currently at least 55 companies involved in nanotube fabrication and that production levels will soon be reaching 1 kg/day in some companies. For example, Japan’s Mitsui and Co. built a facility in April 2003 with an annual production capacity of 120 tons of carbon nanotubes. The company plans to market the product to automakers, resin makers and battery makers. In fact, the industry has grown so quickly that Holister believes that the number of nanotube suppliers already in existence are not likely to be supported by available applications in the years to come. Fried also supports this contention, stating that the ‘carbon nanotube field is already over-saturated’.
Note: A complete list of references can be found by referring to the original text.
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