Vibration Energy Harvesting with PZT Micro Device

A micro power generator harvesting vibration energy by resonant inertial oscillation of a piezoelectric laminated cantilever with proof mass was designed, fabricated, and characterized. The active part with 2 µm thick PZT on 5 µm silicon was equipped with interdigitated electrodes to achieve higher voltages. A coupling constant k2=5% was derived from the difference in resonance frequencies at low and high impedance. At optimal load impedance, a voltage of 1.6 V and an output power of 1.4 µW was measured with a 0.8x1.2 mm cantilever having an active area of 0.8x0.4 mm, excited with 2g at 870 Hz.