Smart dust mote forerunners

We have demonstrated a 138 mm/sup 3/ autonomous uni-directional sensing/communication mote that optically transmits a measure of the ambient light level. We have also developed a 63 mm/sup 3/ autonomous bi-directional communication mote that receives an optical signal, generates a pseudorandom sequence based on this signal to emulate sensor data, then optically transmits the result, although it has only been demonstrated in a bench configuration at this time. The latter system contains a micromachined corner cube reflector, a 0.078 mm/sup 3/ CMOS chip that consumes 75 /spl mu/W, and a Mn-Ti-Li cell, but we have also demonstrated operation from an /spl sim/2 mm/sup 2/ solar cell. These motes allow us to demonstrate necessary concepts of Smart Dust such as optical data transmission, data processing, energy management, miniaturization, and system integration.