Developing MEMS DC electric current sensor for end-use monitoring of DC power supply: Part II - MEMS-scale device with five-PZT plates

A passive (power-less), non-contact MEMS DC electric 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). In present study however, a MEMS-scale prototype DC sensor, comprised of 5 parallel PZT plates, was micro-fabricated for preliminarily examination. A micro magnet was fixed by manipulator onto the PZT cantilever tip to the theoretically pinpointed position of the center plate. Different from the results of the macro-scale prototype DC sensor, impulsive piezoelectric output voltages accompanying with a gradual decrease in decay were detected when the applied DC electric current was varied from 0.5 A to 2.5 A. A linear relationship between the detected peak value of the impulse output voltage and the applied DC electric current was also obtained but with a higher slope compared to the result of the macro-scale hand-made prototype DC sensor.