Feasibility of inductive communication between millimeter-sized wireless robots

This paper shows the feasibility of inductive data transmission between millimeter-sized (2 x 2 x 1 mm(3)) swarm robots. To fulfill the size restraints, the coils used for inductive transmission were fabricated by micromachining technologies. Since the induced signal at the receiving coil was very small due to the low coupling coefficient, a high amplification gain of the signal amplifier was necessary. Transmitter and receiver electronics for data transmission were constructed and the quality in data transmission between two 2 x 2 mm(2)-sized micromachined coils was evaluated. With a continuous power consumption of 270 mu W in the transmitter, data transmission was successful without communication error up to a distance of 7 mm, which was considered sufficient to enable 2 x 2 mm(2) robots to behave as a swarm within the given operation area.