Researchers are developing a method to recharge drones mid-flight using laser beams directed at receivers placed beneath their wings. The lightweight receiver has been designed to capture energy from a ground-based laser and convert it directly into electricity. The top layer snaps up laser light and converts it into electricity, while the bottom layer harvests the waste heat to extract even more energy. Energy conversion efficiency In laboratory tests using a green laser beam, the system converted 38.49% of incoming laser energy into usable electricity. Apart from the power receiver itself, engineers must build rapid tracking optics that can lock onto a moving target miles in the air.