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Nanohorror

Posted on 14 Jul 2003 at 16:39

Last year, the US government's National Nanotechnology Initiative spent just 0.07 per cent of its research budget on investigating the environmental and health impacts of nanotechnology. Safety research is gradually increasing, but it's still a long way from providing a body of evidence on which to base health and safety regulations. 'In light of this astonishing negligence,' says Pat Mooney, executive director of ETC, 'and because consumers are already being exposed to synthetic nanoparticles, the call for a mandatory moratorium is the only reasonable policy response.'

A moratorium is what Bill Joy is campaigning for too but, while some regulation no doubt will emerge, a full moratorium on further nanotechnology research seems unlikely. Not only are many of the world's biggest and most powerful multinational companies involved in this work, but governments are desperate not to be left behind. The US government budgeted $710 million (£425m) for nanotechnology this year, while Europe stumped up $1.2 billion (£719m).

The result was a rash of articles in the US, half of which seemed to be saying 'our budget's really bigger than yours because you cheated the sums', while the other half were proclaiming the eclipse of the US unless it immediately outspent those upstart foreigners. Japan, despite its economic woes, is spending $500 million (£299m) this year, and even less heavily industrialised countries such as India are actively pursuing nanotechnology research.

Quite apart from national pride and commercial lobbying, governments are also subject to the enormous momentum of the military. A vast amount of nanotechnology research, perhaps even the majority, has been driven by military needs and military or defence-industry funding.
One of the earliest schemes to emerge publicly from this was surveillance dust, or Smart Dust. Funded by the Pentagon's DARPA (Defense Advanced Research Projects Agency), the University of California in Berkeley was commissioned to produce remote sensors no larger than a grain of sand. Powered by sunlight, temperature gradients, ambient radio waves or other free energy sources, these devices would detect movement, infrared, radio transmissions or whatever else was required and communicate it back to a remote observer. Initially intended to be dropped in a cloud over enemy positions to signal movements of troops and armour, this dust also has obvious applications in civilian covert surveillance and tracking.

How close to reality all of this is remains unclear, but pea-sized devices able to communicate over 21km were reportedly demonstrated a couple of years ago, so it's reasonable to assume that the technology has become smaller and better since then. One of the most important factors in designing Smart Dust is balancing the energy budget. Whatever technology is on-board must work within the minuscule amounts of energy the device can absorb from its environment or store temporarily in a microscopic battery. It's estimated that practical computation could run at 1 picojoule per instruction and that gathering a unit of data from a sensor would need 1 nanojoule. Given that current battery technology could store at least 1 joule in a cubic millimetre, a reasonably small particle of surveillance dust should run for months or years even without an energy top-up.

Transmitting the data back to base is potentially the biggest energy user, so the Berkeley team has been using an almost passive system based on microscopic corner reflectors. These consist of three tiny mirrors arranged at right angles to each other like the corner of a cube. Widely used as radar reflectors on boats, corner reflectors will always send a beam back to its source. This means that if the dust is broadly illuminated by a distant laser, each particle can return a message simply by turning its mirrors on and off. This obviously requires far less energy than actively transmitting the same data.