This simple, ingenious design keeps drones from breaking when they crash

At first glance, FlexiQuad looks like a small drone. Just one more buzzing thingy doing its flying thing. Then you see it crashing against a tree. A regular drone would crash and fall to the ground, but this one bounces back from the tree trunk and happily keeps flying along. The key to this trick is a hollow ring design crafted from flexible materials. [Image: Courtesy Luca Girardi] Today, almost every quadcopter uses four stiff arms bolted to a central body that holds its battery, bra...