An anonymous reader writes: Researchers at the University of Hawaii have turned bubbles of gas into non-mechanical 'microbots' that they propel and steer with a laser [http://spectrum.ieee.org/automaton/robotics/industrial-robots/microbots-made-from-bubbles-and-lasers]. The laser heats up specific areas of the fluid that the bubble are in, and temperature gradients push the fluid towards the hot area, moving the bubble along. By using an array of lasers, the researchers can control the speed and direction of multiple bubble bots independently; this capability is not possible with other types of microbots, such as those controlled by a magnetic field, which affects all robots simultaneously. The University of Hawaii researchers hope their non-mechanical microbots can be used to assemble and manipulate microscopic structures, including live cells. In one experiment, they used the bubble bots to position 100-m-diameter glass beads to form the letters 'UH.'