Tape-Like Vibrational Energy Harvesters Using Flexible Fluorinated Polyethylene Propylene (FEP) Piezoelectret as Transduction Material

Abstract

Energy harvesting is a promising strategy utilizing renewable energy to power low-power-consumption electronics, such as wireless sensor network (WSN) nodes and wearable electronics. In this article, a tape-like vibrational energy harvester, using flexible fluorinated polyethylene propylene (FEP) piezoelectret films as transduction material, is reported. Due to a specific air-filled parallel tunnel structure, the FEP piezoelectret films in this study exhibit both significant longitudinal and transverse piezoelectric effects and could be made into tape-like flexible transduction devices. The results show that the experimental data are consistent with the theoretical prediction and the finite-element method (FEM) calculation. For a device with an effective area of 18 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times25$ </tex-math></inline-formula> mm and a seismic mass of 0.195 g on one edge, the output power at a resonant frequency of 16 Hz amounts to 3.1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> for an acceleration of 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${g}$ </tex-math></inline-formula> . Owing to the tape-like and flexible transduction elements, the power generated by the device can be enhanced readily by either enlarging area of the transduction elements or multiplying a few transduction elements in series or parallel to meet the power requirement of electronic devices, which makes the practical application flexible.