Washington, March 7 : Scientists are all set to insert micro-systems into living insects, so that they can be used to spy on the enemy. Inspired by Thomas Easton's 1990 novel "Sparrowhawk", in which animals enlarged by genetic engineering were fitted with implanted control systems, the Defence Advanced Research Projects Agency (Darpa) is preparing to do the same with insects.
The aim of the scientists is to insert micro-systems into insects as they undergo metamorphosis. In fact, the plan is that their organs will grow around the chips and wires that make up the remote-control devices.
Darpa's main goal is to create cyborg insects that can fly at least 100 metres from their controller and land within 5 metres of a target and stay there until commanded to buzz off again.
Although this goal is still in the future, the agency has made remarkable advances.
In a series of videoclips shown at a conference in Tucson, a tobacco hawkmoth with wires connected to its back lifts and lowers one wing, then the other, then both, in response to signals delivered to its flight muscles.
The clips were filmed at the Boyce Thompson Institute in Ithaca, New York, where a team led by Dr David Stern implanted the flexible plastic probes into tobacco hawkmoth pupae seven days before the moths emerged.
A probe is embedded in each set of flight muscles on each side of the moth and a connection protrudes from the moth's back. This can be hooked up to the tether wires which also deliver control signals and power.
As the Darpa researchers increase the frequency of the muscle stimulation, the moth's wings beat faster, approaching take-off speed. In another clip, the moth is flying, tethered from above, when electrical impulses applied to muscles cause it to swerve left or right.
Meanwhile another Darpa-funded group led by Dr Michel Maharbiz at California University has implanted electrodes into the brains of adult green June beetles, near brain cells that control flight.
When the team delivered pulses of negative voltage to the brain, the beetles' wing muscles began beating and the bugs took off. A pulse of positive voltage shut the wings down, stopping flight short, and by rapidly switching between these signals, they controlled the insects' thrust and lift.
The challenge now is to shrink the components to hide as many of them as possible inside the insect. They are also looking to harness power from the insects themselves and resolve how the insects will be guided to a target.