Performance of a piezoelectric bimorph for scavenging vibration energy

Abstract

We analyze the performance of a piezoelectric bimorph in the flexural mode for scavenging ambient vibration energy and evaluate the dependence of the performance upon the physical and geometrical parameters of the model bimorph. The analytical solution for the flexural motion of the piezoelectric bimorph shows that the output power density increases initially, reaches a maximum, and then decreases monotonically with increasing load impedance, which is normalized by a parameter that is a simple combination of the physical and geometrical parameters of the scavenging structure, the bimorph, and the frequency of the ambient vibration, underscoring the importance for the load circuit to have the impedance desirable by the scavenging structure. The numerical results illustrate the considerably enhanced performances achieved by adjusting the physical and geometrical parameters of the scavenging structure.

Self-Contained Resonant Rectifier for Piezoelectric Sources Under Variable Mechanical Excitation

“…Indeed, a considerable portion of the rectifier circuit losses is due to the forward voltage drop of the bridge diodes (D B ). The bridge diode losses are estimated to be [by (25)] 0.8 mW. The losses can be reduced by using a synchronous rectification scheme, in which the diodes (D B ) are replaced by a switch with low "ON" resistance to thereby reduce the forward voltage drop to a negligible value [27], [28].…”

“…The poling direction of the two PZ bimorph inserts is across the thickness dimension. Therefore, it is the lateral coupling k 31 , which mainly drives the PZ response [25]. The actuator was excited by a sinusoidal voltage source of 40 V pk−pk .…”

Connected Vibrating Piezoelectric Bimorph Beams as a Wide-band Piezoelectric Power Harvester

“…In this article we reserve Q for the material quality factor and, therefore, we are using N for the shear force in bending. This notation is the same as the one used in Jiang et al (2005). At the cantilevered left end of a beam the boundary conditions are At the right end there is no bending moment:…”

“…Piezoelectric materials are natural candidates for devices that scavenge ambient vibration energy by converting mechanical energy into electric energy, which will then be used for powering small electronic devices of a very low power requirement, (e.g. Cho et al, 2000;Engel et al, 2000;Ha, 2001;Taylor et al, 2001;Roundy et al, 2003;Jiang et al, 2005;Yang et al, 2005). More references can be found in a recent review article by Anton and Sodano, 2007.…”

Coupled electromechanical analysis of MEMS-based energy harvesters integrated with nonlinear power extraction circuits

“…They believed that the possible reason for the deviations between theoretical and experimental results is that a linear damper can not completely model the mechanical loses and electro-mechanical coupling. Linear analyses were also conducted by modeling the harvesting circuit by an arbitrary impedance connected directly to the harvester output terminals (Jiang et al 2005) or a resistive load connected through a diode rectifier bridge (Lu et al 2004).…”