Researchers at Toyota Central R&D Labs have created an insect-sized flying robot that can flap its wings. The robot is powered by an RF energy receiver with an impressive power density of 4900 W / kg.

Small drones tend to run for a very short time due to a limited power supply, and Toyota Central R&D decided to work around this obstacle.

Currently, non-contact power supplies using electromagnetic waves are increasingly finding practical use in various products, but how they can be used in small flying robots has not been previously studied. Therefore, the main goal of the researchers was to create an insect-sized flying robot capable of charging using contactless, wireless technology. The robot they created is equipped with a flapping piezoelectric drive powered by a 5 GHz dipole antenna.

“One of the key features of our robot is highly efficient flapping, which is achieved through the use of powerful monocrystalline piezoelectric material and a low-loss design with two wings facing each other like clapping hands. This design provides a power-to-weight ratio comparable to that of live insects, ”co-author Takashi Ozaki told TechXplore.

A key problem in miniature robots is thermal runaway caused by power loss. To solve this problem, Ozaki and his colleagues have optimized the design of their robot so that the heat-generating components are not close to each other.

In addition, the researchers used an RF energy receiver with a power density significantly higher than the power density of standard lithium polymer batteries of the same mass. This has greatly improved the efficiency and uptime of the robot.

“I think our most important finding is that a circuit weighing up to one gram can receive and process high power in excess of 1 W at a distance via radio frequency waves. This suggests that not only flying robots, but also various other devices that require a lot of power in a small size, can be implemented without batteries, ”Ozaki said.

The robot, created by Ozaki’s team, weighs only 1.8 g, which is 25 times less than other micro-devices powered by radio frequencies. In the future, it may be used to perform complex tasks involving penetration into cracks, pipes or other very confined spaces.