Tiny robot imitates caterpillar

Dartmouth unleashes a prototype thinner than a hair that moves on a little silicon foot.

Michael Kanellos Staff Writer, CNET News.com
Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas.
Michael Kanellos
2 min read
Researchers at Dartmouth College have invented a robot so small that an entire army of 200 of them could march across an M&M.

The prototype robot, which measures 60 microns wide and 250 microns long, is the smallest untethered mobile robot ever invented, according to professor Bruce Donald. A human hair on average is about 90 microns wide. (A micron is a millionth of a meter.)

Rather than rolling on wheels, the robot moves by scrunching itself up like a caterpillar. Turning is accomplished by planting a silicon "foot" down and pivoting around it. To avoid sticking or breakdowns, the robot doesn't include hinges or wheels. In all, the device contains two actuators for movement, one that controls forward motion and another that controls turning.

Guidance and instructions come from a grid of electrodes beneath the "feet" of the robot. Hence, they do not have to be connected to wires.

"When we say 'controllable,' it means it's like a car; you can steer it anywhere on a flat surface, and drive it wherever you want to go," Donald said in a statement.

The robot also moves quite fast. The machine can take tens of thousands of 10-nanometer steps every second (a nanometer is a billionth of a meter). Thus, it's possible the robot could move its entire body length in under a minute.

Like many other robots coming out these days, the micromachine at Dartmouth is designed to perform jobs that are too difficult or dangerous for people. Someday, tiny machines like this could be used to repair integrated circuits inside a computer, or to check areas for nerve gas or other hazardous chemicals before humans go in. Conceivably, these robots, a class of microelectrical mechanical systems, or MEMS, could be used by doctors to repair damaged tissue.

The research was funded in part by the Department of Homeland Security, one of the many governmental agencies plowing money into robotics. The Department of Defense, which has commissioned projects on autonomous helicopters and cars, has set a goal of making one-third of all combat vehicles robot-driven by 2010.

While U.S. universities and companies are spending their energy on these types of hazard robots, Japanese companies are working on entertainment and companion robots.

Donald will further describe his research at the 12th International Symposium of Robotics Research, scheduled for Oct. 12-15 in San Francisco.