They may not be "robots" as most have come to expect, but these so-called microrobots developed by a team of researchers from the University of Hawaii at Manoa do have at least one thing in common with many of their mechanical counterparts: lasers. As IEEE Spectrumreports, the bots themselves are actually nothing more than bubbles of air in a saline solution, but they become "microrobots" when the laser is added to the equation, which serves as an engine of sorts and allows the researchers to control both the speed and direction of the bubbles.
Engadget
See also:
newgadgets, Researchers power microbots made of bubbles with lasers