A Statically Balanced Compliant Ortho-Planar Mechanism for Low-Frequency Energy Harvesting

Abstract

Abstract The usually high eigenfrequencies of miniaturized oscillators can be significantly lowered by reducing the stiffness through static balancing. In this work, a mechanical design for a statically balanced compliant ortho-planar mechanism is proposed. The mechanism was prototyped using laser micro-machining and subsequently preloaded through packaging. The statically balanced property of the mechanism was experimentally validated by a measurement of the force-deflection relation. A piezoelectric transducer was added and the resulting energy harvesting device was tested at low-frequency vibration of 2Hz. Compared to a reference device, an almost sixfold increase in performance was observed due to the static balancing. Therefore, it was found that the use of static balancing can improve the power output of piezoelectric energy harvesters for low-frequency vibrations.