Nerve Probe Controls Cyborg Moth in Flight
Posted on February 21st, 2012 in RC Car Videos | No Comments »
Half-moth, half machine, a new generation of remote-controlled insects could one day be applied as spies GOVERNMENT spooks want cyborg insects to snoop on their enemies. Biologists want to tap into the nervous systems of insects to understand how they fly. A probe that may be implanted into moths to control their flight could aid satisfy both parties. One day, it could even aid rehabilitate humans who have had strokes. The US Defense Advanced Research Projects Agency (DARPA) has been running a programme to construct machine-insect interfaces for years but electrodes implanted to stimulate the brains or wing muscles of insects were not precise enough. Now Joel Voldman of the Massachusetts Institute of Technology and colleagues have designed a unique, flexible neural probe that may be attached directly to an insect’s ventral nerve cord (VNC), which, along with the brain, makes up the central nervous scheme in insects. Another reason former attempts have not been exclusively successful was because the impedance of the electrodes did not match that of the insect’s tissue. This probe is made of a polyimide polymer coated with gold and carbon nanotubes, and it is impedance is much closer to that of nerve tissue. One end of the probe is a ring that clamps around the VNC. The inside of the ring has five electrodes which stimulate distinct nerve bundles within the VNC. Attached to the probe is a wireless stimulator, which holds a radio receiver, as well as a battery and a device to generate electrical pulses. The team implanted the device in the abdomen of a tobacco hawkmoth (Manduca sexta). As it weighs less than half a gram, it is easy for the moth to carry. “Their wingspan is the width of your hand,” says Voldman. “These are big guys.” Testing on tethered moths revealed that stimulating one side of the VNC made the moth’s abdomen turn one way, and vice versa (Journal of Neuroscience Methods, DOI: 10.1016/j.jneumeth. 2011.11.026). The amount the abdomen turned depended on the strength of the current, which ranged from when it comes to 1 to 10 microamperes. The team then implanted the device in untethered moths and sent commands remotely. The moths turned left or right whenever the suitable signal was delivered (see video at newscientist.com/article/dn21431). “This is a major advance,” says insect neurobiologist Roy Ritzmann at Case Western Reserve University in Cleveland, Ohio. DARPA hopes this kind of control will one day grant intelligence agencies to use insects to carry surveillance instrumentation and spy on unsuspecting enemies. The researchers likewise found that the comparatively low current required to control the moth meant they were capable to pick up nerve signals. This will have to grant them to gain an clear or deep perception into the impulses that make a moth fly, something that has not been possible with former electrode designs. The low current was also less damaging to the moth. Voldman’s team is now talking to neurobiologists to see if the probe could be applied in humans. “It turns out there are a bunch of cylindrical nerves in persons that are in regards to the same size,” says Voldman. Electrodes that stimulate nerve bundles could aid rehabilitate persons who have lost mobility after a stroke. So will insect cyborgs soon become a reality? “It is a step toward that goal, but we are still a long way away,” says Ritzmann. “To genuinely get to a cyborg, we would need to tap where behavioural commands come from and often that is the brain. We are just starting to comprehend these brain circuits.” If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication division firstborn for permission. New Scientist does not own rights to photos, but there are a potpourri of licensing choices available for use of articles and graphics we own the copyright to. |
February 20, 2012 at 7:34 am