Solar Cell Powering with Integrated Global Positioning System for mm3 Size Robots

new concept of a solar cell powering with integrated Global Positioning System (GPS) for microrobots is proposed. The main idea is to use a projector to transfer energy and to provide global positioning information to the robots that are equipped with multi-segment solar cells on their top. First tests with a 3000 ANSI lumens beamer projecting a white image showed a scavenged power of 7.1 and 27.8 µW/mm2 for commercially available crystalline silicon solar cells and for thin film amorphous silicon solar cell respectively. Regarding the global positioning system, the projector sends regularly a sequence of 17 images and the robot decodes them using two independent solar cell segments acting as photodiodes in order to calculate its own position and orientation inside a defined arena. First experimental results on a large scale prototype are presented. For 2.65 x 2.65 mm2 photodiodes the x, y and angular resolution are 4 mm, 3 mm and 6 degrees respectively inside an arena of 512x384 mm2 and the duration of the sequence is 0.85 s.