UC Berkeley researchers are designing a millimeter-long robotic flea that uses a tiny rubber band to launches itself into the air. The current prototype is seven millimeters long and tests have shown that it could jump 20 centimeters off the ground. The graduate student who led the research, Sarah Bergbreiter, is part of UC Berkeley's effort to build Smart Dust, tiny wireless sensors that form ad hoc networks. Several years ago, I wrote an article for Lab Notes about Sarah's previous work adding legs to Smart Dust to transform the sensors into miniscule mobile robots. This latest approach involves a rubber band two millimeters long and just nine microns thick, one tenth the diameter of a human hair. From Technology Review:
Bergbreiter, in collaboration with the Smart Dust Project, created the rubber band by cutting a circular strip measuring... out of a thin sheet of silicone using a very fine infrared laser. It was then hooked onto the robot's stretching mechanism using nothing more than a pair of ultraprecision tweezers, a stereoscopic microscope, and a steady hand. This was a bit like playing the children's game Operation, only harder, says Bergbreiter.
To test the robot prototype, Bergbreiter hooked it up so that rather than the bot actually jumping, its leg was positioned to kick an object. This allowed her to calculate the energy being released. So far Bergbreiter has only tried partially stretching the rubber band, which would achieve a jump of about 12 millimeters for the 10-milligram robot. However, she says that based on the results of this test, a full stretch would be capable of producing jumps as high as 200 millimeters, and they would cover roughly twice as much ground horizontally.