Optimum design of a piezoelectric MEMS generator for fluid-actuated energy harvesting

This paper reports the optimum design, fabrication and characterization of a piezoelectric MEMS generator for fluid-actuated energy harvesting. Depending on the specific load scenario optimum beam shapes of piezoelectric cantilevers are investigated by theoretical estimations and related experiments. A point load at the free-end of a cantilever requires a triangular beam shape. Compared to a classical rectangular shape the electrical area energy density is three times larger. A maximum area energy density value of 35 nJ/mm² is measured for the triangular beam shapes. A uniform load as occurring for fluid-actuated energy harvesting calls for a triangular-curved beam shape and is also superior to classical geometries.