Passive temperature compensation in piezoelectric vibrators using shape memory alloy–induced axial loading

Piezoelectric materials have been widely studied as vibration energy harvesters in civil and mechanical systems, given their energy conversion ability and high mechanical to electrical coupling properties. Several external environmental effects, such as temperature, alter the performance of these transducers, thus limiting the longevity and the efficiency of the powered systems. Several techniques are applied to improve the harvesters’ properties and offset the environmental effects. These techniques include the optimization of the piezoelectric material, the use of matching networks to increase the power transfer, and, most importantly, the tuning of the harvester’s resonant frequency to match the fundamental frequency of the input excitation vibration, ensuring a maximum response. In this article, the effects of temperature variations on the energy harvesting characteristics of a bimorph cantilever lead zirconate titanate piezoelectric beam are studied. A proposed mechanical tuning, based on the application of an axial load to compensate the temperature effect, is presented. Mathematical models, which describe the combined effects of temperature and axial load on the natural frequency of the piezoelectric device, are derived. Finally, a fully passive temperature compensation mechanism is proposed. Experimental results are also shown to validate the presented results and the proposed concept.

[1]  Michael J. Anderson,et al.  A resonant frequency tunable, extensional mode piezoelectric vibration harvesting mechanism , 2008 .

[2]  Daniel J. Inman,et al.  Removing effects of temperature changes from piezoelectric impedance-based qualitative health monitoring , 1998, Smart Structures.

[3]  Wei Ren,et al.  Temperature dependence of the complete material coefficients matrix of soft and hard doped piezoelectric lead zirconate titanate ceramics , 2007 .

[4]  Frank T. Fisher,et al.  A coupled piezoelectric–electromagnetic energy harvesting technique for achieving increased power output through damping matching , 2009 .

[5]  Yiannos Manoli,et al.  NOVEL ELECTRICALLY TUNABLE MECHANICAL RESONATOR FOR ENERGY HARVESTING , 2008 .

[6]  Yang Zhang,et al.  Toward self-tuning adaptive vibration-based microgenerators , 2005, SPIE Micro + Nano Materials, Devices, and Applications.

[7]  L. Brinson.  One-Dimensional Constitutive Behavior of Shape Memory Alloys: Thermomechanical Derivation with Non-Constant Material Functions and Redefined Martensite Internal Variable , 1993 .

[8]  D. Inman,et al.  Frequency Self-tuning Scheme for Broadband Vibration Energy Harvesting , 2010 .

[9]  Kenji Omote,et al.  Temperature Dependence of Shear Piezoelectric Properties of Poly(vinylidene fluoride) Studied by Piezoelectric Resonance Method , 1996 .

[10]  Nizar Lajnef,et al.  Tunable Energy Harvesting From Ambient Vibrations , 2010 .

[11]  M. G. Prasad,et al.  A vibration energy harvesting device with bidirectional resonance frequency tunability , 2008 .

[12]  Daniel J. Inman,et al.  Estimation of Electric Charge Output for Piezoelectric Energy Harvesting , 2004 .

[13]  Daniel J. Inman,et al.  Resonant manifestation of intrinsic nonlinearity within electroelastic micropower generators , 2010 .

[14]  P. Wright,et al.  Resonance tuning of piezoelectric vibration energy scavenging generators using compressive axial preload , 2006 .

[15]  Daniel J. Inman,et al.  An experimentally validated bimorph cantilever model for piezoelectric energy harvesting from base excitations , 2009 .

[16]  Ephraim Suhir,et al.  Effect of Temperature on Vibrations of Physically Nonlinear Piezoelectric Rods , 2006 .

[17]  Yuantai Hu,et al.  A piezoelectric power harvester with adjustable frequency through axial preloads , 2007 .

[18]  D. Inman,et al.  Nonlinear piezoelectricity in electroelastic energy harvesters: Modeling and experimental identification , 2010 .

[19]  P. Woias,et al.  Bidirectional frequency tuning of a piezoelectric energy converter based on a cantilever beam , 2009 .

[20]  Karla Mossi,et al.  Studying the effects of temperature on energy harvesting using pre-stressed piezoelectric diaphragms , 2007, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.