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Cybugs: a bold idea hatches

Sydney Morning Herald

Thursday February 17, 2011

Pat Sheil

In an experiment that sounds more like fiction than reality, US researchers have engineered a hybrid organism that's part insect, part machine, writes Pat Sheil. There's nothing new about remote-controlled aircraft. The earliest ones date to World War I and with the development of the transistor, it became possible to make radio receivers and control systems small enough to fit into the model planes and helicopters you see buzzing about in parks, piloted by gleeful geeks with hand-held transmitters.But in trying to get much smaller than that, engineers have come up against problems of scale that until recently have proved intractable. To get down to the size of a large insect, for example, you still need an engine to drive the aircraft, radio and on-board control systems to steer it and a source of energy to make it all function. If you want to build a plane the size of a beetle, it is just about impossible because the batteries, engines and electronics are far too heavy for the lift available from wings so small.But in a breakthrough that is as creepy as it is ingenious, engineers and scientists have managed to get around many of these problems by using off-the-shelf technology that's cheap, efficient and proven over many years in all manner of environments - real, live insects.From an engineering standpoint, it makes perfect sense. Bugs come ready-equipped with their own engine and sophisticated navigation systems. They simply eat to refuel and millions of years of evolution have turned insects into efficient flying machines. All that is needed is a way to override their own navigation systems and a human pilot can send them to any destination within the critters' natural flight range.Flying machines? Surely this is a living animal, not a machine. Well, it's actually hard to say - welcome to the rapidly blurring distinction between electronic engineering and animal husbandry.Several groups in the US have been working on controlled-insect flight research, funded by the Defence Advanced Research Projects Agency through its Hybrid Insect Micro-Electro-Mechanical Systems project (HI-MEMS), which aims to create "hybrid cybernetic organisms".One of the most successful is headed by an associate professor of electrical engineering at the University of California, Berkeley, Michel Marharbiz. Marharbiz's team have reached the point where they can remotely control a beetle (they settled on the heavy-lift, five-centimetre Mecynorrhina torquata) to take off, turn right, turn left and land. They are working on finer controls that will allow much more complex flight paths in three dimensions.So how do the researchers make the connection from the transmitter to the beetles so they can receive their instructions? It's a delicate business, done by hand, one bug at a time. Beeswax is used to hold the anaesthetised beetles in place while small holes are pierced in the cuticle on their head and underneath their wings. Steel-wire electrodes, already soldered onto an electronic control board, are then threaded through the holes to the required depth in the brain. The board, including a tiny computer that runs control software, a radio receiver, an antenna and a battery, is strapped to the back of the beetle like a backpack and the bug is ready to be flown.A member of Marharbiz's HI-MEMS team, Hirotaka Sato, established that the Mecynorrhina beetles could be "switched on and off" by applying repeated positive and negative-voltage pulses to electrodes implanted between the left and right optic lobes of the insects' brains and that stringing varying numbers of these flight initiation pulses together allowed him to control the vertical tilt of the beetle's flight and thus control altitude. For left-right control, he turned to the muscles. Direct stimulation of the basalar muscle, found underneath the wing, with low-frequency electric pulses acted as basic turning commands.Given the project is funded by DARPA, the researchers are under some pressure to come up with "cybernetic organisms" that will eventually have military applications and they have a way to go yet. Obviously, a large beetle with an electric backpack flying about a room would not exactly represent a breakthrough in stealthy surveillance, a point Marharbiz readily concedes."Can you imagine," he says, "if you were in a meeting and a giant beetle, half the size of your palm, completely non-native to your environment and wearing a circuit board on its back, suddenly careened in through the window and crashed onto your computer screen?"But these are early days - it seems quite possible to insert the entire electronic package into the pupa stage of the beetle, which would not only allow closer integration of the circuitry with the beetle's neurons but be invisible after metamorphosis. The electronics of external control would then literally become part of the animal. Marharbiz says further miniaturisation of the electronics will eventually lead to the remote control of insects as small as a fly.The implications are both scary and fascinating. Kamikaze insects carrying nerve gas into enemy tanks? A bug on the wall that is also bugging your room, can follow you around, let people know where you are and, if need be, kill you?Or perhaps major breakthroughs in the merging of electronics and biology that could lead to treatments for everything from spinal damage to neurological and muscular diseases in humans. No one knows but it's hard to shake off the creepiness factor.For some, the announcement in December 2009 by Cornell University engineers of an experimental nuclear power source for the insects adds to the science-fiction nightmare quality of it all. An electrical engineering associate professor, Amit Lal, and a graduate student, Steven Tin, presented a prototype in-flight control system. Most insects are too light to carry batteries that would last long enough to be useful and obvious logistical problems would prevent regular battery changes regardless. Lal and his group at Cornell have devised a tiny generator, powered by the decay of a radioactive isotope of nickel, which could function for much longer than the lifespan of any insect. Such a device could also be incorporated into the body during the creature's pupal stage.But visions of swarms of tiny radioactive cyborgs sweeping into your home under the control of a twisted human mind are, at least for now, far-fetched and even the more fundamental ethical questions don't really take into account our dealings with animals in the past 100,000 years."The bioengineering is not the frightening part. After all, we've been domesticating animals forever," says a professor at the UC Berkeley department of geography, Jake Kosek. "The real question is how these military-funded technologies will be used in the future." How big a leap is it from fencing, droving, taming and selectively breeding animals to controlling their movements with brain implants? How different is a transmitter and a set of electrodes from, say, a saddle and a whip?Writing in December's edition of Scientific American, Marharbiz sounds almost relieved that working with beetles "allows us to postpone many of the deeper ethical questions ... among other things, that would become more pressing if this work took place on vertebrates."But these questions will certainly arise before long. As Marharbiz points out: "The discipline of seamlessly merging the organic with the synthetic is only beginning."REMOTE-CONTROLLED BUGS THEGOODNEWS...They could be used to locate trapped victims in natural disasters and to inspect dangerous infrastructure such as underground pipes, bridges and mines. The technology could also lead to tiny transmitters being implanted in people‚„s brains to operate prosthetics.THE BAD...They could be used as weapons to trigger terrorist attacks, drop poison or high-gradeweapons or to assassinate individuals. They could also be used to spy on people ‚€ť the bugs would literally bug people.ANDTHE UGLYEventually the technology could even lead to remote control of higher animals, including humans.WHAT ABOUT REFUELLING?The material being tested for powering insects is nickel-63 (Ni- 63), a mildly radioactive isotope with a fewextra neutrons in its nucleus.When it decays, it emits beta particles ‚€ť high-energy electrons that are relatively innocuous. Its half-life is 12 years.SO IS THIS REALLY POSSIBLE? We use military technology that once seemed far-fetched every day. Military‚€śfunded research has brought us the internet, the computer mouse, global positioning systems and lasers used in everything fromCD players to supermarket checkouts. About 70 per cent of all the engineering research conducted in the US is funded by the Department of Defence.WHY USE BUGS?There‚„s no shortage of potential aircraft in an insect army. According to Harvard biologist E.O.Wilson, the Earth hosts about 10 quintillion (10 18) insects, comprised of about 8 million distinct species. THEY HAVE STAMINA...The painted lady butterfly, from North Africa to Iceland, has the longest migration distance of any insect ‚€ť more than 6000 kilometres. Some butterflies have been logged flying at up to 6000 metres...AND THEY ARE FAST Sphinx Moths, right, can travel at 52km/h.

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