cellorg biological/chip hybrid

Living bacteria have been incorporated into an electronic circuit to produce a sensitive humidity gauge.

The device unites microbe and machine, taking advantage of the properties of both to make for a supersensitive sensor.

"As far as we know, this is the first report of using microorganisms to make an electronic device," says Ravi Saraf, a chemist from the University of Nebraska, Lincoln, who developed the 'cellborg' with his student Vikas Berry.

"This is essentially a first step towards a biological computer, and would have many applications," says Steve Ripp, a biotechnologist at the University of Tennessee, Knoxville. Ripp was part of a team that developed a sensor that relied on glowing bacteria to detect chemicals. But in their system, the electronic circuits were simply reacting to the bugs, and they weren't hooked up to each other, he notes. Saraf's humidity sensor melds the two together.

Ripp says that interest in these cellborg circuits is growing fast. "If you detect a chemical with a biological device, you not only sense its presence but also its effect on a living system," he says.