The sensor is big because it’s mechanical — it has moving parts. The section on the top spins around constantly, so the lasers can build up a 360-degree map. This also limits the refresh rate of the LIDAR image: the sensor can only know where something is when it’s bouncing a light off it, and although it can accurately infer where an object is based on its past location, direction of travel, and speed, it’s still a blind-spot of sorts. Researchers from MIT and DARPA might have a solution though — a new version of LIDAR that shrinks the light-bouncing apparatus onto a chip that’s smaller than a grain of rice. Writing for IEEE Spectrum, researchers Christopher Poulton and Michael Watts claim that their prototype sensors “promise to be orders of magnitude smaller, lighter, and cheaper than LIDAR systems available on the market today.” They could be the eyes of future robots.