Flea-like robot takes giant leap in bot locomotion

[Nipuna]

Video: Tiny robot jumps like a flea

AS ANNOYING and itchy as they are, you have to admit one thing about fleas: they certainly know how to jump. Now they have inspired a jumping robot - a leap forward in the attempt to get small automatons to move a long way in a hurry.

For a flea to jump, a muscle attached to its femur first compresses an elastic protein called resilin, locking it in a squashed position using a latch. Then a small trigger muscle releases the latch, flinging the flea through the air up to, and in some cases over, 100 times its body length.

To put a spring in their robot's step, Minkyun Noh and colleagues at Seoul National University in South Korea turned to a shape memory alloy called nitinol. Such alloys have crystalline structures that allow them to flip between two stable positions when heated, or when an electric current passes through them.

The team built three springs out of nitinol that fold and lock in the same way as a flea's leg does. By tethering their prototype to a power supply they were able get it to jump up to 60 centimetres - 30 times the robot's own length (IEEE Transactions in Robotics, doi.org/jmb).

Their next step is to work out how to give their prototype an on-board power supply and keep the leaping robot upright during flight and on landing. "Getting the power supply and electronics on-board is a challenge due to the light weight of the robot," says Noh.

"The idea of slow priming and fast release is very interesting and their exploitation of new materials here is exciting," says Chris Melhuish, director of the Bristol Robotics Laboratory in the UK. "Perhaps future robot tools like small drills and needles might also be actuated in a similar way."