1. Introduction
Emerging miniaturization technologies (e.g. micro machining and MEMS) will someday enable the creation of large numbers of extremely small robots, with fully self-contained sensors, actuators, computation, and power. While such robots individually are of limited use, thousands of them, operating as a coordinated swarm, could conceivably accomplish a wide range of significant tasks [5], [6], [9]. Ultimately, swarms of small scale robots should be able to achieve large-scale results in tasks such as surveillance, reconnaissance, hazard detection, path finding, payload conveyance, and small-scale actuation. However, to fully exploit the prospects of miniaturization, we must first address the challenges posed by the need for humans to interact with, communicate with, and coordinate the activities of thousands of tiny cooperating entities.