They measured available deflection, force and power output from oscillatory movements at different locations on a beetle with an unmounted piezoelectric beam and showed that up to ~115 microwatts power generation is possible. Two initial generator prototypes were fabricated, mounted on a beetle, and harvested 11.5 microwatts and 7.5 microwatts in device volumes of 11.0 mm3 and 5.6 mm3 respectively, from 85 Hz-100 Hz wing strokes. A final prototype was designed to enable minimum disturbance of free-flight while maximizing power output. ANSYS simulations predict an output of 101.6 microwatts.
A final energy scavenger prototype was designed to provide a lower spring constant, while still occupying a limited area (5 mm X 5 mm) and maximizing strain on the piezoelectric layer, by employing a spiral beam geometry. For realization of the device, reliable low temperature solder bonding of piezoceramics was developed, and re-polarization and laser ablation of bulk piezoelectric layers were characterized.