Electromagnetic induction type micro generator combined with MEMS air turbine and multilayer ceramic magnetic circuit

This paper proposes miniaturized electromagnetic type power generators that compose of an air turbine by the MEMS (Micro Electro Mechanical Systems) technology and a magnetic circuit by the multilayer ceramic technology. Small and high energy density power supplies have been required with the increase in power consumption of electronic equipment. However, conventional power supplies have been reaching the theoretical limit. Accordingly, miniaturized power generators to replace the secondary battery have been studied. In this paper, two types of MEMS air turbine generators are proposed. The generators are the single-phase type MEMS air turbine generator and three-phase type, respectively. The generation capability of the single phase magnetic circuit was preliminary evaluated by a rotating permanent magnet which was attached to a spindle machine. When the rotational speed was 380000 rpm and a load resistance was 1 ohm, the output power reached to 1.47 mVA. Combined with MEMS air turbine, the generator showed maximum rotational speed of 30,000rpm, and the output power was 1.74 micro VA at load resistance of 1 ohm. The magnetic circuit of three phase type was evaluated by the spindle machine. When the rotational speed was 380000 rpm and a load resistance of 1 ohm, the output power was 3.3 mVA. Also, maximum rotational speed of the rotor of the MEMS air turbine generator was 18,000rpm, and the output power was 1.41 micro VA.