Critical issues in the commercialization of nanotechnologies.

SUMMARY

It is now recognized that nanotechnology is a set of tools for manipulating matter at the nanometre level that can be applied to any manufactured product. There is no discrete nanotechnology industry but a set of different industry sectors each with its discrete set of issues, particularly those relating to real and perceived risks. However, there are linkages between them that need to be considered, particularly in the production and application of nanomaterials.

The general consensus among studies of development and application of nanotechnologies is that there will be about a decade between realization of a new technology and its commercial application. There are several critical issues which need to be considered in this step. The role of standards for manufactured products, of toxicity testing for nanoparticles, and of clinical trials for health products, will be crucial. Many of the potential applications raise safety and health issues which need to evaluated. Acceptance of nanotechnology applications by society is dependent on the society's awareness of their benefits outweighing risks.

Key Words

nanotechnologies; commercialization of new technologies; standards; health and safety risks of nanotechnologies; social acceptance of new technologies

Introduction

Nanotechnology is the term given to those areas of science and engineering where phenomena that take place at dimensions in the nanoscale (a nanometer [nm] is one billionth of a metre) are utilised in the design, characterization, production and application of materials, structures, devices and systems. At this size level, materials show different physical, chemical and biological properties. Although many technologies have incidentally involved nanoscale structures for many years, it is only in the past two decades that it has been possible to actively and intentionally modify molecules and structures within this size range. For example, the feature sizes on silicon chips are now around 60 nm. Nanoparticles of zinc oxide used in transparent sunscreens are around 30 nm.

There are numerous definitions in the literature which cover science and technology at the nanoscale. Thus the report of the Royal Society/ Royal Academy of Engineering in the UK (RS/ RAE 2004) has the following definitions:

A simpler definition used in a recent report in Australia (PMSEIC 2005) is:

The significant feature from both approaches is that nanotechnology is a set of tools and processes for manipulating matter at the nanometer level which can be applied to any manufactured product. There is considerable confusion over the concept of a nanotechnology industry. It needs to be stressed at all levels that there is no discrete nanotechnology industry but a set of different industry sectors, each with its discrete set of issues, particularly those relating to real and perceived risks. There are linkages between them which need to be considered, particularly in the production and use of nanomaterials.

However, just as phenomena occurring at the nanoscale may be quite different to those at larger dimensions--and thus exploitable for the benefit of mankind--so nanoscale processes and products may expose humans and the environment to new risks. This would raise new environmental, social, legal and ethical issues which could restrict the development of nanotechnologies. Attention has been focused on the fate of free nanoparticles generated in production, and either intentionally or unintentionally released into the environment, or actually delivered directly to individuals through the use of a nanotechnology-based product. Free particles in the nanometre range raise particular environmental, health and safety issues since their toxicology cannot be deduced from that of the same material at the macroscale. This stems from two factors dependent on size: namely, the larger surface/volume ratios leading to higher activity; and, the potential for nanoparticles to penetrate cells more easily than larger particles.

OPPORTUNITIES FOR APPLICATIONS OF SCIENCE AND TECHNOLOGY AT THE NANOSCALE

The opportunities can be divided into three main categories (Tegart 2004):

1. Molecular engineering inspired by biotechnology

This covers several sectors: firstly, nanobiotechnology and nanomedicine; and, secondly, molecular manufacturing. In the first group of nanobiotechnology and nanomedicine, the scale of living systems involved is in the range from micrometers down to nanometers; it is possible to combine biological units such as enzymes with man-made nanostructures. One of the most significant impacts of nanotechnology is at the bioinorganic materials interface. By combining enzymes and silicon chips, it is possible to produce biosensors. These can be implanted in humans or animals to monitor health and to deliver corrective doses of drugs. They have the potential to produce improved health care for humans at lower cost and to improve animal productivity. Development of human biomedical replacements--such as artificial skin, smart bandages and pacemakers--is also dependent on nanotechnology.

In the longer term there is a vision of making robotic machines, called assemblers, on a molecular scale, that are capable of constructing materials an atom or a molecule at a time by precisely placing reactive groups. This could lead to creation of new substances not found in nature--so-called molecular manufacturing. However, there is enormous potential for revealing how self-replicating structures with exceptional properties are produced in nature--so-called biomimetic engineering.

2. Electronic technology based in semiconductors

This covers the sectors of nanoelectronics, nanophotonics and quantum computing. There is potential to increase the capacity of microchips up to 1 billion bits of information per chip. However, the costs of production are increasing dramatically and there is intense study around the world to determine the point in physical scaling where it either becomes physically unfeasible or financially unattractive to continue the trend towards reducing the size and increasing the complexity of microchips. At a size less than about 50 nm particles begin to follow the laws of quantum physics rather than classical physics and properties such as magnetism and electric charge change rapidly. Nanoscale structures such as quantum dots offer a path to a new type of computer--the so-called quantum computer. There is extensive research on the fabrication of electronic structures on the nanometer scale based on entirely new physics. Devices under development include lasers for optoelectronics, ultrafast switches, memory storage devices for computers and, ultimately, devices controlled by single electron events.

3. Devices and processes based on new materials

Creative materials and surface science is critical to further advancement of nanotechnologies. One of the interesting properties of particles of materials such as metals or ceramics at the nanometre size level is their very high surface area per unit volume--which has potential for speeding-up catalytic reactions and biochemical and pharmaceutical separations, and thus improving the efficiency of many processes. Reduction in size to the nanoscale level results in an enormous increase of surface area--so that relatively more atoms or molecules are present on the surface, thus enhancing the intrinsic reactivity. The definition of nanoparticles as being less than 100 nm is perhaps too simple since it does not take account of the dramatic size effects in the range below 100 nm. For example, a particle of size 30 nm has 5% of its atoms on its surface, at 10 nm 20% of its atoms and at 3 nm 50% of its atoms (RS/RAE 2004).

Nanomaterials can be produced from a variety of material classes as: carbon-based nanomaterials, nanocomposites, metals and alloys, biological nanomaterials, nanopolymers, nanoglasses and nanoceramics. Each covers a wide range of different chemical compositions and of hazardous and non-hazardous forms. Some of these are manufactured and sold in bulk to intermediate companies making specialised products while others are manufactured as part of an integrated production process in the sectors noted above.

Most of the material classes can be produced in a variety of shapes as:

* nanoscale in one dimension; for example, thin films, layers and surfaces;

* nanoscale in two dimensions; for example, nanowires and nanotubes;

* nanoscale in three dimensions; for example, nanoparticles of regular or irregular shape, fullerenes (spherical molecules about 1 nm in diameter, comprising 60 carbon atoms arranged in a cage structure), dendrimers (polymeric molecules) and quantum dots (small nanoscale particles of semiconductors whose optical properties can be controlled by size).

Such nanomaterials can be produced by either the 'bottom-up' approach (i.e. building-up from individual atoms or molecules through chemical synthesis self-assembly or positional assembly), or the 'top-down' approach (i.e. breaking-up bulk materials into nanoparticles through grinding, milling or precision etching).

APPLICATIONS OF NANOTECHNOLOGIES

Products based on nanotechnologies are already widely used (e.g. paints, pharmaceuticals, micro-electronic devices and composite materials), and the global market is estimated to be worth over US$40 billion. Rapid market growth in these and new areas is anticipated, possibly to US$1 trillion by 2015-2020. Various estimates are available, on different bases, about the likely future global markets for products using nanotechnologies. However it is meaningless to refer to a discrete set of markets, because nanotechnologies can potentially impact on virtually every industry sector and their products, in different ways and at different times. Some of the impacts will be evolutionary while others will be revolutionary. There will be significant changes to existing industries and new industries will be created.

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