RoboBees were running out of juice, until now

20 May 2016

Tiny microbots are often held back by energy use, with battery power both heavy and limited. But that’s all about to change, after scientists took inspiration from a balloon sticking to a wall.

Static electricity is one of the more entertaining scientific discoveries a child makes. You rub a balloon against a t-shirt and see it stick to a wall, or lift your hair up off your head.

The memory is so lasting in some people that it follows them through school, college and then into the lab, like it did with Moritz Graule, an engineering student at Harvard.

Pondering ways to get a longer lifetime out of mini robots – which could be used in disaster relief programmes in future – Graule and his colleagues thought that static electricity could help.

The problem was these RoboBees use up energy all the time, wings constantly motoring to keep them in the air. But what if they could latch on to things, like a bird does with its feet?

When you rub a balloon on a wool sweater, the balloon becomes negatively charged. If the charged balloon is brought close to a wall, that negative charge forces some of the wall’s electrons away, leaving the surface positively charged.

The attraction between opposite charges then causes the balloon to stick to the wall.

The RoboBee has an electrode patch on its edge, which, when supplied with a tiny charge, can stick to many surfaces. Once the charge is cut, it is released.

“In the case of the balloon, the charges dissipate over time, and the balloon will eventually fall down,” said Graule. “In our system, a small amount of energy is constantly supplied to maintain the attraction.”

When in use, the patch needs 1,000 times less energy than when the RoboBees are flying, with Graule and his team working on ways to work onboard batteries into the plan, shifting away from these tethered prototypes.

Check out these 10 other amazing robots inspired by nature.

Bees image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic