After writing about cyborg insects and their possible use in emergency situations in my Nov. 23, 2011 posting, I started wondering how the insects could be made to dig down into the earth to find people trapped underground, etc. As it turns out, scientists have already been working on that problem, from the Jan. 6, 2012 news item on physorg.com,

An insect’s internal chemicals can be converted to electricity, potentially providing power for sensors, recording devices or to control the bug, a group of researchers at Case Western Reserve University report.

The finding is yet another in a growing list from universities across the country that could bring the creation of insect cyborgs – touted as possible first responders to super spies – out of science fiction and into reality. In this case, the power supply, while small, doesn’t rely on movement, light or batteries, just normal feeding.

“It is virtually impossible to start from scratch and make something that works like an insect,” said Daniel Scherson, chemistry professor at Case Western Reserve and senior author of the paper.

“Using an insect is likely to prove far easier,” Scherson said. “For that, you need electrical energy to power sensors or to excite the neurons to make the insect do as you want, by generating enough power out of the insect itself.”

…

The key to converting the chemical energy is using enzymes in series at the anode.

The first enzyme breaks the sugar, trehalose, which a cockroach constantly produces from its food, into two simpler sugars, called monosaccharides. The second enzyme oxidizes the monosaccharides, releasing electrons.

The current flows as electrons are drawn to the cathode, where oxygen from air takes up the electrons and is reduced to water.

After testing the system using trehalose solutions, prototype electrodes were inserted in a blood sinus in the abdomen of a female cockroach, away from critical internal organs.

…

The researchers found the cockroaches suffered no long-term damage, which bodes well for long-term use.

More technical details are available in the news item although I notice there is no mention of ethics. I’m happy to see that there doesn’t seem to be any long-term damage to any of the beasties they’ve tested so far but should we really take control of them in this way?