MICROBOTS: A team of engineers at SRI International has harnessed simple, magnetically levitated microbots to build structures and perform other sophisticated tasks at small size scales. Image: Courtesy of SRI International
A pioneering research institute that introduced the computer world to the mouse, hypertext and networks is now setting its sights a bit lower. A team of engineers at SRI International, a nonprofit contract research and development lab in Menlo Park, Calif., has harnessed simple, magnetically levitated microbots to build structures and perform other sophisticated tasks at small size scales.
Many such floating microbots could be made to work in concert, something like mechanical ant colonies, to construct objects and carry out many other useful applications, says Ron Pelrine, chief scientist at SRI's Robotics, Engineering Research and Development Division. He suggests, for example, that they would be suited for micro-assembly jobs in plants that fabricate micro-electromechanical system (MEMS) chips or rapid prototyping of novel structures with embedded electronics such as sensors and portable diagnostic devices. They might also do small-scale tasks in biological and medical fields such as cell printing or forming complex tissue-growth media.
The current laboratory demo devices range from a 0.1 to one centimeter across—about the size of a pinhead to somewhat smaller than the diameter of a AAA battery—tiny enough to carry lightweight objects (such as short lengths of carbon fiber) by attaching them temporarily to manipulator arms using only the feeble surface tension of water droplets.
Despite their petite size and basic simplicity, operation of the precision-controlled devices is fast and highly repeatable, characteristics that SRI researchers demonstrate in the video below. The air hockey puck–like devices can move as much as 217 body lengths a second and offer potential motion repeatability to within an estimated 40 nanometers, roughly the diameter of a virus.
The next video exhibits the technology's further potential for use in future microscale factories: The magnetic mechanisms are shown scooping up objects onto mini forklifts, actuating syringes and executing rudimentary electric arc–cutting tasks. Another video segment displays the bots moving across surfaces held at steep angles and upside-down as well.
A novel path to microbotics
Microbot research has been growing worldwide in recent years because of the new availability of the necessary parts—minuscule motors, actuators, batteries and so forth, according to Pelrine, who notes, "A lot of the recent work was done by hobbyists, and they've demonstrated more and more capabilities."