Modeling Energy Harvesting From Membrane Vibrations in COMSOL

R.K. Kapania, R.C. Singh, and C. Sultan
Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

This paper presents an ongoing effort, motivated by developing self-contained sensors for structural health monitoring of inflatable structures, to model the process of extracting useable electrical power from the mechanical vibrations of thin, prestressed membrane structures. Energy harvesting from mechanical vibrations of these structures may provide enough power to operate both the sensors as well as wireless devices used to transmit data to a remote data collection device. COMSOL Multiphysics is used to estimate the response of a piezoelectric patch placed onto a thin-film membrane to induced vibrations. The model incorporates both the piezoelectric and purely structural responses. As this system involves the conversion of mechanical strain energy into electrical power, the piezo patch is modeled as a generator. By comparing the numerical estimate of the power harvested to an analytical equation in terms of the Rayleigh coefficients, the damped behavior of the system due to the equivalent load resistance is found via a time-dependent analysis in COMSOL.