Researchers have developed a commercial drone that can resist damage by changing from rigid to soft in the event of an accident.

The EPFL, in Lausanne, Switzerland has developed a drone that takes inspiration from the natural world, such as birds and wasps that are used to flying into objects, such as trees, telegraph poles and windows, just shaking of the collision (most of the time) rather than falling to their death.

“Wasp wings display dual stiffness, that is the ability to reversibly transition between rigid and soft states, which provides mechanical resilience without impairing flight performances,” the researchers explained.

“The wings of wasps contain a flexible resilin joint… This design allows the wing tip to slightly flex during flight (rigid state), but reversibly crumple… during collisions (soft state). If the dual-stiffness behavior is impaired… the rigid wings undergo severe tear during collision.

“Therefore, this design provides crash resilience by effectively preventing wing overload during collisions without compromising flight capabilities.”

Although methods already exist to prevent damage occurring when a drone crashes, such as surrounding the propellers in a cage and allowing some kind of bounce back in the design, for example introducing flexible elastic couplers to take the strain away from the moving parts, nothing has been designed to keep the drone in its purest form, until now.

EPFL’s drone features a a flexible frame that attaches to the rest of the drone with magnets. When a crash happens, this frame will detach to absorb the impact without damaging the internals. When it’s safe, the frame will re-attach, allowing the drone to carry on as intended.

“This allows combination of the advantages of both rigid and soft systems: stability and rapid response to user commands during flight, leading to flight performance equivalent to a drone equipped with a standard rigid frame, and crash resilience like a soft system,” the researchers explained.

“The experiments showed a satisfying survivability of the frame of the drone, that withstood roughly 50 collisions with no permanent damage.