Video: RoboBees Can Land And Perch On Surfaces With Static Electricity

By R. Siva Kumar - 20 May '16 13:42PM

Amazing flying microrobots called RoboBees fuelled by static electricity have been created by a team of Harvard roboticists. They have the ability to perch during flight so that they can save energy like bats, birds, and butterflies.

"Many applications for small drones require them to stay in the air for extended periods," said Moritz Graule, who conducted the research at Harvard University and is the first author of the study. "Unfortunately, smaller drones run out of energy quickly. We want to keep them aloft longer without requiring too much additional energy."

The team studied the perching method used by animals to conserve energy but found that adhesives, or talons, do not completely support perching techniques for tiny robots. Hence, the team used electrostatic adhesion or the method behind static-charged balloons that stick to walls.

When you rub a balloon onto a wool sweater, it leads to negative charging. When it comes close to a wall, it can force some of the wall's electrons away, leading to a positive charge on the wall. Hence, the attraction between both charges made the balloon stick to it.

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

The RoboBee uses an electrode patch and a foam mount to absorb shock. With a weight of about 100 milligrams, it weighs as much as a real bee. When the electrode patch gets charged, it can stick to almost any surface, and gets detached with a cut in the power supply.

"One of the biggest advantages of this system is that it doesn't cause destabilizing forces during disengagement, which is crucial for a robot as small and delicate as ours," Graule said.

As the patch can be fuelled by 1,000 times less power to perch than to hover, the RoboBee can conserve energy and also expand its operational life. Currently, it can only perch when it is overhanging or on ceilings, but the team hopes that in future it can develop a mechanical design to enable perching on surfaces.

"There are more challenges to making a robust, robotic landing system but this experimental result demonstrates a very versatile solution to the problem of keeping flying microrobots operating longer without quickly draining power," said Kevin Ma of Harvard University and co-author of the study.

The findings will be published in the May 20 issue of the journal Science