Researchers develop impact-resistant drone with flexible ring frame

Engineers Luca Girardi and Stefano Mintchev at ETH Zürich have prototyped a drone that replaces the traditional rigid central body with a flexible, ring-shaped frame. The design, dubbed FlexiQuad, distributes the battery and electronic components evenly around the perimeter of the drone, using the mechanical properties of anisotropic stiffness to remain rigid vertically while allowing the structure to flex during impacts.

By drawing inspiration from the flight mechanics of birds and insects, the team engineered a structure that is roughly a thousand times more flexible than conventional quadcopters. This enables the device to absorb kinetic energy upon hitting an obstacle, rather than sustaining damage to the frame or rotors. In testing, the 14-ounce prototype reached speeds of over 50 mph and navigated through restricted gaps by deforming its frame.

While the current design excels in physical resilience, the research team is working on addressing technical challenges such as camera stabilization after an impact. By utilizing reinforcement learning, they are training the drone to use motion sensors to automatically regain stability mid-flight after a crash. The inventors suggest that the simplicity of the fiberglass laminate frame could keep manufacturing costs minimal.