The concept of soldier ants may not be far away from a Department of Defense proposal to field an army of remote-controlled insect-cyborg scouts.The Hybrid Insect Micro-Electro-Mechanical Systems (HI-MEMS) program is the responsibility of the Defense Advanced Research Projects Agency (DARPA), which on March 9 announced that it was soliciting research proposals on the technology. These insects would be outfitted with sensors and a wireless transmitter that could enable them to send data on conditions in places inaccessible to human troops. The goal of the program is to produce a sensor-enabled insect with a 100-yard range that could be placed within five meters of a target using electronic remote control and, potentially, Global Positioning System (GPS) technologies.The technical specifications around the cyborg-insect project have not been determined, said a DARPA spokeswoman. However, she said it may be possible to use the insects as "micro unmanned air vehicles" to go into areas that humans can't reach or that are too dangerous. For example, the insects could collect signatures of explosives inside buildings or caves and transmit relevant data back to their operators, she said. There's some interest in using radio frequency connectivity to enable the insect's sensors to report back to the operator, the spokeswoman said.The use of insects for fact-finding tasks isn't new, according to the DARPA proposal. Previous research found that feeding, mating and temperature-change responses prevented the insect-subjects from "performing reliably." The HI-MEMS project could correct these irregularities by using some sort of reliable control interface that would be inserted into the insect at selected stages of its development."For example, moths and butterflies transform from eggs to larvae to caterpillars, and finally to flying adult states," stated the DARPA document. "Through each metamorphic stage, the insect body goes through a renewal process that can heal wounds and reposition internal organs around foreign objects, including tiny MEMS structures that might be present."During some of the metamorphic stages, the insects are immobile and can be manipulated without interference from instinctive motion. Inserting MEMS devices during such stages could enable assembly-line like fabrication of hybrid insect-MEMS interfaces, providing a considerable cost advantage."While flying insects such as moths are of "great interest," hopping and swimming candidates are acceptable, as well. The cyborg-insect must also be able to remain still at a target area for indefinite time periods or until it received a prompt from its handler. Among the gear it would carry would be a gas sensor, a microphone and a video camera.The spokeswoman acknowledged there are many challenges to the project, such as how to control the insect's locomotion and how to power the device that would be used. "We have to find a way to scavenge power from the insect to run the device," she said."Certainly, it's not something we've done before." The insect's own heat and power-generating motions could render a battery superfluous. These thermal and mechanical electrical energy-conversion methods, "coupled to the integrated insect platforms," are expected as outcomes of the program, the proposal states.DARPA also stated it would hold a workshop for those interested in submitting proposals to the HI-MEMS program on March 24 in the Arlington, Va., area.