Leech-based robot climbs vertical walls

The natural world continues to inspire designers of robots. The menagerie of creatures on which robots have been based, which already includes geckos, cephalopods and dogs, now includes the squirming, bloodsucking worms of many people’s nightmares: the leech.

While leeches have mainly been notable for their history in medicine and as inspiration for anticoagulant drugs, researchers at Toyohashi University of Technology in Japan and the University of Cambridge have collaborated on exploiting their physical abilities, rather than their feeding behaviour.

Leeches have a peculiar and characteristic method of locomotion, with suction cups at either end of their soft bodies. Holding on firmly to a surface with the suction cup at their rear, they reach forward as far as they can with their heads and attach that cup, then detach the rear and arch forward to bring the rear close to the front, forming their body into a loop, then detach the front and reach forward again. Land-living leeches can move around their mountain or forest environments with few constraints, clinging to a wide variety of surfaces and unconcerned with the orientation or gradient of the surface on which they move.