Bistable energy harvester using easy snap-through performance to increase output power

Abstract

This paper describes a novel bistable piezoelectric energy harvester that collects kinetic energy from ambient vibrations for a sustainable powering of microelectronics. The host structure is a beam pre-deformed into a sinusoidal form, with piezoelectric layers on its upper and lower surfaces. A U-shaped torsion device is integrated into the middle of the beam to facilitate a more efficient break through the potential barrier. The harvester is tested under different conditions by a vibration test system. Experimentally, the peak open-circuit output voltage is 1377 mV (when the pre-deformation height is 10 mm and the mass of the block is 40 g, with a frequency range of 6.4–11.5Hz.). At this point, snap-through occurs in the generating beam. As the load resistance of the harvester’s external circuit increases, the output voltage increases sharply and then flattens; the output power first increases and then decreases. At a load of 47 kΩ the harvester reaches its optimal output state with a maximum average output power is 0.179 mW.