The bigger picture: Smallest robotic crab

Engineers from Northwestern University in Evanston, Illinois, have developed the smallest-ever remote-controlled walking robot – a tiny peekytoe crab. Just a half-millimetre wide, the minute crabs can bend, twist, crawl, walk, turn, and even jump.

The researchers also developed millimetre-sized robots resembling inchworms, crickets, and beetles. Although the work is exploratory at this point, researchers believe their technology might bring about micro-sized robots that can perform practical tasks inside tightly confined spaces. The research was published in the journal Science Robotics.

The robot is constructed from a shape-memory alloy material that transforms to its ‘remembered’ shape when heated. In this case, the researchers used a scanned laser beam to rapidly heat the robot at different targeted locations across its body. A thin coating of glass elastically returns the corresponding part to its deformed shape upon cooling. As the robot changes from one phase to another – deformed to remembered shape and back again – it creates locomotion.