Submission to Royal Society and Royal Academy of Engineering by Professor Peter Dobson, Academic Director of Oxford University Begbroke Science Park, UK.
The hype and hysteria surrounding this topic is very worrying to those who
have worked in the field for the past 30 years. The welcoming fact is that it
has raised both public and scientific awareness in a subject that is exciting,
crosses scientific disciplines and really does have the capacity to “provide
solutions” to many technologies.
The most surprising aspects of this survey are that two learned societies feel the need to undertake this survey, and that the timing of this is some years after the scientists and engineers realised that the topic was at the centre of attention. This should have been discussed several years ago. I will follow the guidelines of the study and address the specific questions.
Nanoscience and nanotechnology are the studies and applications of the manipulations and properties of matter at the atomic and molecular scale ie: at dimensions of the order of nanometres. Essentially that is what chemistry has been about for the past 100 years.
As in all applied science and technology, there is often a 10-15 year time lag from the first scientific publication to the full application of anything. In this particular case it is now possible to define some “time lines” and for convenience I will sub-divide these into three:
a) 2-3 years: The applications will range from incremental improvements to the uses of nanoparticles, either in their “free” form or as nanocomposites. In the former case we will see new catalyst applications (eg: combustion catalysts in diesel and other fuels) or cases in which inhibition of chemical reactivity can be designed (sunscreens, pollutant control) and in nanocomposites that have new properties by virtue of size effects. The first of several biomolecular devices will appear, mainly in the field of biosensors (some are already very close to market). Some examples of self-assembly and the use of soft lithography to mass-produce nanostructures will appear.
b) Up to 5/6 years: There will be some new applications for the low dimensional forms of carbon in the form of fullerenes (large molecules and nanotubes). These may be functional composites (both structural and electrical) or they may be electron emitting nanotubes. It is unlikely to be electronic processing devices in this time-frame. There could also be some electronic device applications in other nanomaterials such as thin layer nanoparticle-based transistors, solar cells and displays. These will take longer than first forecast because of issues in the large scale fabrication and in the science/technology of making the electrical contacts. A likely topic to emerge will be new opto(electronic) materials that are based on nanocomposites not made by the “conventional” epitaxial semiconductor routes. Some of these may be made by soft lithography, a very promising way of mass producing nanostructures. There will be an increase in the range of demonstrator applications of inorganic/biomolecule devices and these will range from new bio-materials to sensors and therapy applications. There will be closer linkage between the areas of genomics, proteomics and metabolomics across the physical/life sciences divide.
c) Up to 10/12 years: The much hoped for molecular or quantum dot electronic devices may appear, but much will depend on the level of financial support. More realistically we may see a wide range of bio-nanoscale applications ranging from sensors to micro-power sources. Bio-mimetic structures of all types should become much more prevalent. The reality of this time-frame depends critically on the advances of the 5/6 year period.
Health, Safety and Environmental Impact:
There are uncertainties in this area but they are being addressed by a few scientists who have been working in the field for the past decade or so. The main causes of concern are the toxicity of nanoparticles suspended in the air or in absorption via the skin. The former relates to the uncertainties about why asbestos (and certain types of silica) particles are toxic. The latter relates to the coating of particles by lipophilic layers than can aid rapid absorption via the skin. In both cases the issues are surface composition, radius of curvature and surface energy and the precise way in which toxicity occurs. In some instances (eg: older forms of sunscreen) harmful effects are produced by photocatalytic free radical formation, which is ironically the basis of “self cleaning window and ceramic surfaces”.
Social and Ethical Issues:
There are no serious issues here apart from the rules that apply to all existing science issues. The hysteria about self-replicating nanorobots is based on science fiction and should be treated as all fiction, a story with no real foundation in fact. However, we should recognise that “size” does impart new physical and chemical properties and this fact needs to be included in risk assessments.
Apart from recognition that “size” can alter the physical and chemical properties, the other area that need to be addressed is that of bio-molecule modification. Given that we have the means to alter molecules at the atomic and protein building-block level we do need to have available the means to identify what we have done and assess the implications, preferably quickly and without recourse to “animal experiments”.
This country is lagging far behind the rest of the industrial world in terms of Government support. It is putting in “too little too late”, suggesting that some of the decision makers are completely out of touch with the real world. The recent announcement of £90M from DTI over a six year period is ludicrous given that it will also go into MEMS and other Microsystems as well as true “Nanotechnology”.