Most roboticists working on drones these days are outfitting their flying machines with more complex sensors for more intelligent flight. The Gimball robot from the EPFL in Switzerland is a refreshing counter example. It doesn't use an array of accelerometers, gyroscopes, and cameras to orient itself, spot obstacles, and avoid them. It's designed to mimic the flying capabilities of an insect. In other words, it just bounces off of things.
The Gimball uses a set of three gimbals to protect itself from collisions. A lightweight elastic cage sphere rotates independently around the robot, which is powered by a pair of propellers and two guiding fins. The whole thing weighs only 370 grams, or 0.8 pounds. Carbon fiber rings support the cage, which can absorb all sorts of bumps without taking a bit of damage. The only sensors the Gimball uses for flight are a compass and an altitude sensor.
To test their insect-inspired creation, Ph.D student Adrien Briod and engineer Przemyslaw Mariusz Kornatowski set the Gimball loose in a forest with nothing but a compass direction to go on. It flew a few hundred meters--and bounced off some trees along the way--while continuing to reorient itself and fly merrily on its way.
The Gimball is also outfitted with a camera, and Brod hopes the durable design could be used in disaster situations to navigate collapsed buildings and search for survivors. Another practical use case: Kids. The Gimball would take them at least twice as long to break as a normal drone.