Harvard's RoboBee successfully perched using electrostatic charge

We are already benefiting from the perks of drone technology in many different fields. Micro aerial vehicles (MAVs) belong to the drone family as well, but they did not yet make their big mark in the world of technology. The wait just got a little shorter, as a scientific team produced an innovative design and successfully perched its MAV. These insect-like robots are, in certain aspects, more practical than the traditional drones, but specific challenges arise with their use. One of these, is the relatively short operational time, which is being tackled by the idea of perching.

MAV’s lookalikes from the animal kingdom use perching to regain energy. For an MAV to be deployed on a monitoring mission, where it could operate beyond the scope of a traditional drone – due to its size, it needs a longer operational time, and perching is one of the ways to achieve it. Until now, it has been mostly tested on larger, bird-like drones, but an MIT team tested a design on Harvard’s RoboBee. The designs used so far relied on mechanical grippers, dry adhesives, magnets, and even needles. This team wanted the technology to be very energy efficient, applicable to all surfaces, capable of repetition of the maneuver, and smooth transition back to hovering. Electro-adhesion was the answer.

Scheme depicting the use of electrostatic perching design

The whole perching system had to be very small and light as the RoboBee only weights 84mg. The circular electrodes attached to the top of the robot were only 16mg, keeping the weight of the whole drone around the weight of an actual bee. The communication as well as the charge for initiating the perching was still provided by wires, but the results were promising. The drone first had to be hovering stable under the target for certain amount of time, and only after reaching certain stability criteria, the maneuver was initiated. The main success lies in the fact that keeping the drone attached to the surface required only <7 μW of power (depending on the surface) which is far less compared to the 19 mW required for the flight and hovering.

When fully developed, this device could be of tremendous help to search and rescue teams, and for air/ecosystem monitoring. A working perching system represents a n important step towards the finalization of this technology.