Nonlinear Dynamics of Electroelastic Micropower Generators: Implications and Applications
Friday, September 24, 2010 - 11:30am
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Within the past decade, advances in small-scale electronics have reduced power consumption requirements such that mechanisms for harnessing ambient kinetic energy for self-sustenance are a viable technology. Such devices, known as *energy harvesters*, may enable self-sustaining wireless sensor networks for applications ranging from Tsunami warning detection to environmental monitoring to cost-effective structural health diagnostics in bridges and buildings. In particular, electroelastic materials such a lead-zirconate-titanate (PZT) are sought after in designing such devices given their superior efficiency in transforming mechanical energy into the electrical domain. To date, however, material and dynamic nonlinearities in the most popular type of energy harvester, an electroelastically laminated cantilever beam, has received minimal attention in the literature despite being readily observed in laboratory experiments. This research proposes first-principles based modeling framework for quantitatively characterizing both the material and dynamic nonlinear effects in a cantilevered electroelastic generator. Nonlinear parameter identification is facilitated by an analytic solution for the generator’s dynamic response. The model is shown to accurately describe amplitude dependent frequency responses in both the mechanical and electrical domains and implications are discussed concerning the conventional approach to design a resonant generator. Furthermore, applications engaging nonlinear dynamic responses are discussed that range from aeroelasticity to purposefully nonlinear devices exploiting multi-stability and hysteresis.