振動発電素子に対する電流変成デバイスの開発

抄録

One candidate of the energy harvesting device in the field of sensor networks is an electrostatic capacitance type vibration power generator that obtains electric energy from the mechanical vibration of a movable mass suspended by spring structures. However, since that type of power generators have commonly very high output impedance, its output signal has over several tens of volt and hence extremely small current within a few micro amperes. Therefore, it is necessary to drop the voltage of the output signal into a few volt and to increase the output current with the high energy conversion efficiency. In view of this situation, we have initiated the development of an electric transformer with an electrostatic micro electro-mechanical systems(MEMS) device for use in electrostatic capacitance type vibration power generators. This device consists of three terminal static comb-drive actuator with a potassium ion electret and operates by the signal at frequencies below a threshold value.