As nanotechnology makes possible a world of machines too tiny to see, researchers are finding ways to combine living organisms with nonliving machinery to solve a variety of problems.
Like other first-generation bio-robots, the new nanobot engineered at the University of Illinois at Chicago is a far cry from Robocop. It’s a robotic germ.
UIC researchers created an electromechanical device–a humidity sensor–on a bacterial spore. They call it NERD, for Nano-Electro-Robotic Device. The report is online at Scientific Reports, a Nature open access journal.
“We’ve taken a spore from a bacteria, and put graphene quantum dots on its surface–and then attached two electrodes on either side of the spore,” said Vikas Berry, UIC associate professor of chemical engineering and principal investigator on the study.
“Then we change the humidity around the spore,” he said.
When the humidity drops, the spore shrinks as water is pushed out. As it shrinks, the quantum dots come closer together, increasing their conductivity, as measured by the electrodes.
“We get a very clean response–a very sharp change the moment we change humidity,” Berry said. The response was 10 times faster, he said, than a sensor made with the most advanced man-made water-absorbing polymers.