Wideband MEMS electrostatic vibration energy harvesters based on gap-closing interdigited combs with a trapezoidal cross section

This paper deals with a fully batch-processed MEMS electrostatic Vibration Energy Harvster (e-VEH) having a half-power frequency bandwidth of more than 30 % thanks to the combination of electrostatic and mechanical non-linearities. The electromechanical transducer is made of bulk-silicon gap-closing interdigited combs with a trapezoidal cross section. Up to 2.2 μW have been harvested at atmospheric pressure for an external acceleration of 1 G at 150 Hz.