The Pentagon is seeking applications from researchers to help them develop technology that can be implanted into living insects to control their movement and transmit video or other sensory data back to their handlers.

In an announcement posted on government Web sites last week, the Defense Advanced Research Projects Agency, or DARPA, says it is seeking "innovative proposals to develop technology to create insect cyborgs," by implanting tiny devices into insect bodies while the animals are in their pupal stage.

As an insect metamorphoses from a larva to an adult, the solicitation notice says, its "body goes through a renewal process that can heal wounds and reposition internal organs around foreign objects, including tiny (mechanical) structures that might be present."

The goal is to create technology that can achieve "the delivery of an insect within five meters of a specific target located at hundred meters away, using electronic remote control, and/or global positioning system." Once at the target, "the insect must remain stationary either indefinitely or until otherwise instructed ... (and) must also be able to transmit data from (Department of Defense) relevant sensors ... includ(ing) gas sensors, microphones, video, etc."

The move follows challenges the agency says it has encountered in its efforts to train insects to detect explosives or other chemical compounds, and to mimic their flight and movement patterns using small robots.

Several years ago, DARPA launched a $3 million project to train honeybees to find landmines. According to a report by the American Forces Press Service, scientists used sugar-soaked sponges treated with explosives to get the bees to identify the smell as a possible food source.

But last week's solicitation says the project didn't work out.

"These activities have highlighted key challenges involving behavioral and chemical control of insects... Instinctive behaviors for feeding and mating -- and also for responding to temperature changes -- prevented them from performing reliably," it says.

As far as the development of purely robotic or mechanical unmanned aerial vehicles -- so-called micro-UAVs -- the solicitation says that developing energy sources both powerful and light enough "present(s) a key technical challenge."

Both sets of challenges "might be effectively overcome" by the development of insect cyborgs, says the solicitation.

The devices DARPA wants to implant are micro-electro-mechanical systems, or MEMS. MEMS technology uses tiny silicon wafers like those used as the basis for computer microchips. But instead of merely laying circuits on them, MEMS technology can actually cut and shape the silicon, turning the chip into a microscopic mechanical device.

The solicitation envisages the implanted device as a "platform" onto which "various microsystem payloads can be mounted ... with the goal of controlling insect locomotion, sens(ing) local environment, and scaveng(ing) power."

"Possible methods of locomotion control may be sensory manipulation, direct muscle interface, or neural interface to the insect," says the document, known as a Broad Agency Announcement. It goes on to say that sensory manipulation, for instance by projecting ultrasonic vibrations or ejecting pheromones, is likely to be species-specific, whereas technology to directly control insect muscles or brains "may be more general."

DARPA believes that the heat and mechanical power generated by the insects themselves as they move around "may be harnessed to power the microsystem payload" eliminating the need for batteries or other power systems.

The objective is to transform the insects into "predictable devices that can be used for various micro-UAV missions requiring unobtrusive entry into areas inaccessible or hostile to humans."

Among potential missions, says the solicitation, would be the collection of "explosive signatures from within buildings, caves, or other inaccessible locations."

Although flying insects like dragonflies and moths are "of great interest," the document says, "Hopping and swimming insects could also meet final demonstration goals."

Implanting the devices during pupation is key, says the document, because "the insects are immobile and can be manipulated without interference from instinctive motion."

As part of their honeybee training project, DARPA glued tiny radio transmitters to the bees, to help track their movement.

The solicitation says that the healing processes which insects go through as they change from larvae into adults "are expected to yield more reliable bio-electromechanical interface... as compared to adhesively bonded systems to adult insects."

Inserting the devices in pupae could also "enable assembly-line like fabrication of hybrid insect-MEMS interfaces, providing a considerable cost advantage," says the solicitation.

DARPA will hold a day-long conference for contractors interested in submitting proposals on March 24