The DelFly robot dragonfly is the lightest fully autonomous robot ever made. It weighs about 20 grams, about the same as 4 sheets of A4 paper. It can fly all by itself. They just plug in the battery and it takes off it flies around it avoids obstacles, keeps its height and can explore unknown environments. The main innovation is a very lightweight and small stereo vision system, which weighs 4 grams, has 2 cameras, and a small embedded computer. They've developed extremely efficient software that processes images from the camera and determines distances to obstacles in the environment. It goes sufficiently fast to work on board in real time, so the DelFly can avoid obstacles.