Visions of good, visions of harm
Some people have recently, publicly (and belatedly) realized that nanotechnology might create new concerns that we should address. Any powerful technology can be used to do great harm as well as great good. If the vision of nanotechnology sketched earlier is even partly right, we are in for some major changes--as big as the changes ushered in by the Industrial Revolution, if not bigger. How should we deal with these changes? What policies should we adopt during the development and deployment of nanotechnology?
Drexler discussed these issues extensively in his 1986 book Engines of Creation, and, in a remarkably prescient essay first published in 1988, called "A Dialog on Dangers," outlined the concerns that have since come to the fore. One solution to these potential problems, proposed by Bill Joy, cofounder and chief scientist of Sun Microsystems Inc., would be to "relinquish" research and development of nanotechnology to avoid any possible adverse consequences.
This approach suffers from major problems: telling researchers not to research nanotechnology and companies not to build it when there are vast fortunes to be made, glory to be won, and national strategic interests at stake either won't work, or will push research underground where it can't be regulated. At the same time, it will deprive anyone who actually obeys the ban of the many benefits nanotechnology offers.
If a ban won't work, how should we best address the concerns that have been raised? The key concerns fall into two classes: deliberate abuse and accidents.
Deliberate abuse, the misuse of a technology by some small group or nation to cause great harm, is best prevented by measures based on a clear understanding of that technology. Nanotechnology could, in the future, be used to rapidly identify and block attacks. Distributed surveillance systems could quickly identify arms buildups and offensive weapons deployments, while lighter, stronger, and smarter materials controlled by powerful molecular computers would let us make radically improved versions of existing weapons able to respond to such threats. Replicating manufacturing systems could rapidly churn out the needed defenses in huge quantities. Such systems are best developed by continuing a vigorous R and D program, which provides a clear understanding of the potential threats and countermeasures available.
Besides deliberate attacks, the other concern is that a self-replicating molecular machine could replicate unchecked, converting most of the biosphere into copies of itself.
While nanotechnology does propose to use replication (to reduce manufacturing costs to a minimum), it does not propose to copy living systems. Living systems are wonderfully adaptable and can survive in a complex natural environment. Instead, nanotechnology proposes to build molecular machine systems that are similar to small versions of what you might find in today's modern factories. Robotic arms shrunk to submicron size should be able to pick up and assemble molecular parts like their large cousins in factories around the world pick up and assemble nuts and bolts.
"Telling researchers not to research nanotechnology and companies not to build when there are fortunes to be made...will push research underground where it can't be regulated"
Unfortunately, our intuitions about replicating systems can be led seriously astray by a simple fact: the only replicating systems most of us are familiar with are biological self-replicating systems. We automatically assume that nanotechnological replicating systems will be similar when, in fact, nothing could be further from the truth. The machines people make bear little resemblance to living systems, and molecular manufacturing systems are likely to be just as dissimilar.
An illustration of the vast gulf between self-replicating biological systems and the kind of replicating robotic systems that might be made for manufacturing purposes is exponential assembly, a technology currently under investigation at our company, Zyvex Corp., in Richardson, Texas. Zyvex is developing positional assembly systems at the micron, submicron, and molecular scale. At the micron scale, using existing MEMS (microelectromechanical systems) technology, we are developing simple pick-and-place robotic arms that can pick up relatively complex, planar, micron-scale parts made with lithographic technology and assemble those planar parts into simple three-dimensional robotic arms that have the ability to pick up specially designed MEMS parts. Called exponential assembly, this replicative technology starts with a single robotic arm on a wafer that then assembles more robotic arms on a facing wafer by picking up parts already laid out in precisely known locations.
While the number of assembled robotic arms can increase exponentially (up to some limit imposed by the manufacturing system), this assembly process requires (among other things) lithographically produced parts, as well as externally provided power and computer control signals to coordinate the complex motions of the robotic arms. Cut off from power, control signals, and parts, a micron-sized robotic arm would function about as well as one of its larger cousins taken from one of today's automated assembly lines and dropped into the middle of a forest.
"Nanotechnology's potential to improve the human condition is staggering: we would be shirking our duty to future generations if we did not responsibly develop it"