Developing MEMS DC electric current sensor for end-use monitoring of DC power supply: Part VI-Corresponding relationship between sensitivity and magnetic induction

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 proposed in our past work (DTIP 2011). A MEMS-scale prototype DC sensor, comprised of 5 parallel PZT plates, was then micro-fabricated for preliminarily examination (DTIP 2012). A novel oscillating type MEMS DC current sensor, comprised of both actuating and sensing elements, was further proposed for two-wire DC electric appliances (DTIP2013). Then 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 (DTIP2014). And a bending type MEMS-scale DC current sensor device with three parallel PZT partition plates, was fabricated for preliminary examination (DTIP2015). In present study, the relationship between magnetic induction and sensitivity of the proposed DC current sensor is discussed both analytically and experimentally. It can be found that the sensitivity increases with the increasing of the magnetic induction, approached by applying the different number of fixed magnets. And the effect of this approaching on the measurement accuracy will be discussed in the future.