Developing MEMS DC electric current sensor for end-use monitoring of DC power supply: Part IV — Cantilever-based magnetic field sensor device

Abstract

A passive (power-less), bending type MEMS DC current sensor to satisfy the increasing needs of DC power supply for monitoring the electricity consumption by either one-wire or two-wire appliance cord was first proposed in our previous work (DTD? 2011). A MEMS-scale prototype DC sensor, comprised of 5 parallel PZT plates, was then micro-fabricated for preliminarily examination (DTD? 2012). Recently, a novel oscillating type MEMS DC current sensor, comprised of both actuating and sensing elements, was further proposed for two-wire DC electric appliances (DTD?2013). Its applicability to constantly measure the DC current without using cord separator was preliminarily verified. The change of the maximum value of the output voltage was found to linearly increase with the applied DC current. In present study however, a beam-shaped cantilever-based magnetic sensor has been proposed with integrating a micro-magnet, expected to be applicable to terrestrial magnetism with a higher sensitivity in the future. The ANSYS analytical model for the proposed cantilever-based device with integrating a micro-magnet was established and the frequency shifts due to the applied exterior magnetic field were preliminarily studied.