7 - Energy harvesting using piezoelectric materials in aerospace structures

Abstract

Piezoelectric energy harvesters (PEHs) are piezoelectric architectures that are smartly designed to maximum capture ambient vibration/motion energy into piezoelectric material and convert the mechanical energy into electrical energy. The critical piezoelectric material properties for energy harvesting are briefly introduced to provide the reader with a basic background. The state-of-the-art piezoelectric energy harvesting technologies have been reviewed. These PEH concepts include the cantilever beam-based unimorph and bimorph PEHs, flextensional PEHs, edge-clamped PEHs, and the advanced PEHs. Flextensional PEHs are the most promising PEH technology on the market because their average power output is at least one order of magnitude higher than cantilever beam PEHs and edge-clamped PEHs. Flextensional PEHs are also relatively easily integrated into aerospace space systems with little effect on flow dynamic control. In addition, flextensional PEHs can be operated in both resonance and off-resonance modes. Cymbal-type flextensional PEH research opened the door to flextensional PEHs. The “33” mode multilayer stack-based flextensional PEH is one of the most promising PEHs for practical application, with advantages such as capturing more mechanical energy into the piezoelectric structure, increasing mechanical to electrical energy conversion efficiency three to fivetimes, and increasing energy storage efficiency with optimized multilayer configuration. The electrical power delivery from a piezoelectric structure to a resistive load and the energy storage issues are addressed. PEH characterization methods are briefly introduced. Finally, suggestions on PEHs for aerospace applications are discussed.