A Self-Powered MEMS Inertial Switch for Potential Zero Power-Consumption Wake-Up Application

A self-powered micro-electromechanical systems (MEMS) inertial switch has been proposed for potential wake-up application without additional power consumption. In comparison with the previous inertial switches powered by constant voltage sources, the proposed device embedded with the charged electret could output a pulse signal without an external power supply. The self-powered inertial switch has two working states: It could harvest vibration energy under excitation of small acceleration when the applied vibration acceleration was smaller than its threshold; It would output a triggering signal once the applied vibration acceleration arrived up to its threshold. The dynamic responses of the switch in the two working states were analyzed. The drop hammer system and the vibrator system were used in conjunction to test the feasibility of the fabricated self-powered inertial switch. The experimental results showed that under excitation of 0.3 g at 137 Hz, the device could work as a vibration energy harvester (VEH), charging the capacitor of the self-charging power unit to 0.8 V in one minute. When a shock with an amplitude of 40 g was applied to the device, a pulse signal was generated. In addition, electrical measurements during energy harvesting indicated durability and adaptability of the device.