Dynamic switching conversion for piezoelectric energy harvesting systems

The current advances in ultra-low power design let foresee great opportunities in energy harvesting platforms for self-powered systems. This paper presents a switching conversion scheme based on active control for harvesting energy with a higher efficiency than traditional approaches. The approach has been validated for piezoelectric energy harvesters with mixed-signal circuital simulations of non-linear equivalent electromechanical systems and a prototype has been developed. The proposed switching converter may increase harvested power of about 30% with respect to solutions based on traditional rectifiers and is expected to achieve up to 755 muW in a train passenger car running at about 100 km/h with a 32 times 6 mm² cantilever with a 35 g mass attached at the free end.