Design and implementation of optical wireless communications with optically powered smart dust motes

Complete electronic and micro-mechanical systems can now be fabricated on the scale of hundreds of microns. Implementing radio frequency wireless communications with such ´smart dust´ is challenging, due to the power required and the small size of any antennas that can be implemented. Optical wireless communications, using a modulated retro-reflector at the smart dust has the advantages of low-power consumption and highly directive channels that allow long communications ranges. In this paper we report the design and implementation of a communications system that uses a base station to communicate with, and power, smart dust motes, over ranges of 10s of metres. A base station that uses holographic beamsteering is described, and dust motes that use silicon ICs to provide communications, power and modulation control. Results indicate the dust mote will operate at a range of over 30m from the base station.