“Researchers at Penn and the University of Michigan have created the world’s smallest, fully programmable, autonomous robots, packing significant capacities into a device smaller than a grain of salt. These are parsimonious little things, barely visible to the naked eye yet able to sense their environment, respond to it and move around in complex patterns. As described in a new paper in the journal Science Robotics, they run on infinitesimally small quantities of energy and gain power from light.”

From Wall Street Journal.