A 3-axis capacitive nonlinear MEMS energy harvester simulation: unidirectivity no more?

Abstract

In the last decades capacitive nonlinear MEMS energy harvesters had shown a significant improvement in terms of an average output power, miniaturization, and overall power density [1]. Though, an orientation of energy harvesting device with respect to the incoming external excitation remains a well-known issue, in response to which 3-axis systems started to emerge [2]. Nevertheless, such a solution had never been demonstrated for nonlinear capacitive MEMS energy harvesting devices. It had been previously shown in literature that a use of nonlinearity in energy harvesting may result in a significant improvement in a device sensitivity, bandwidth, and overall power output [3]. Up to now, energy harvesting devices had been mostly targeting structure monitoring, shock-dependent and biomedical applications, to which choosing a correct orientation can be an important issue [4]. This paper studies three different energy harvesting device configurations that may help to solve this problem, extending the known advantage of large bandwidth and high sensitivity of a nonlinear system to 3 axes.