“Don’t tase me, bro! I’ll have to get all new nanobots!” Electromechanical nanobots, the type that many think of when they hear “nanobot”, would have vulnerabilities. At first it seems it would be difficult to kill such a tiny machine, but wouldn’t a sufficiently strong electromagnetic pulse (EMP) disrupt the operation of the tiny device and possibly “kill” it?
Ridding oneself of a nanobot “infection” could be difficult. If one is carrying helpful nanobots in one’s bloodstream and tissue, and one is “tased”, scanned with a magnetic resonance imaging machine (MRI), or otherwise suffers a strong electrical shock, does one then have to obtain and ingest or inject a whole new batch of the little helpers? Similarly, in a case of nano-warfare where people are afflicted with tiny destructive nanobots, could the little devils be deactivated or purged by a powerful magnetic pulse or electric shock?
Electrical shock might not be effective against nanobots. When living organisms are shocked with electricity, the current of electrons – the part that does the damage – follows the paths of lowest resistance. In most cases these paths are the nervous and circulatory systems, continuously-connected networks of relatively more conductive tissue or fluid. Unless a nanobot was directly in the path such that the current flowed through it, it might not be damaged at all. Also, for current to flow there must be a potential (voltage) difference across it. Are nanobots so small that there would rarely ever be enough potential across their longest dimension as to cause enough current flow to damage them?
The effectiveness of a magnetic method could be limited. A magnetic pulse or field of sufficient strength might have better potential to harm a nanobot, but that would require the nanobot contain a material susceptible to magnetic fields. Unfortunately, a nanobot comprised of carbon or other non-magnetic materials would be untouched by a magnetic field, just as are most life forms.
Biological nanobots might require some different approaches. Of course, nanotechnology experts have been noting for years that the most well developed nanotechnology, living cells and microorganisms, is already in place and doing just fine. Chemical means such as drugs can damage specific microorganisms or encourage the body’s immune system to attack them, so a similar technique might be used to kill nanobots.
What if nanobots could be confused or convinced to go away? I remember a radio news story on NPR a few years ago about fruit orchards in Northwest Ohio where lady bugs (predator insects) were used to keep unwanted pests under control. The fruit farmer had bought millions of lady bugs, huge bags of them, and turned them loose in the orchards only to later in the day watch as his entire investment, clouds of the tiny insects, rose into the air and headed for Indiana. Nanobots are expected to have a lot less movement capability, but that doesn’t mean that a suitable agent couldn’t be introduced or ingested that would make them try to abandon ship, exiting the body through every possible means. It might take days or weeks, but eventually the unwanted devices might leave without harm. Of course, it desirable nanobots were also chased off one would have to obtain more when conditions were such that they would stay to do their beneficial jobs.
In a future when we are using nanobots for many things, getting rid of the little things will be important. There is no question that we will be unable to safely use nanotechnology in medical or military contexts (or any, for that matter) without adequate controls and means for getting rid of them when that is necessary. It will be interesting to see how the technology evolves, and I hope to stay around long enough to gain the benefits of this most interesting direction in science.
As always, I welcome your comments. — Tim