MEMS-based power disconnect for 42-V automotive power systems

We present the design of a micro-electro-mechanical-system (MEMS)-based power disconnect for use with the proposed 42-V automotive power systems. High-voltage power systems are prone to arcing, which occurs during power disconnections. The high arcing current may lead to severe damage on the systems and may expose electric shock hazards to humans. The objective of the MEMS-based power disconnect we propose is to eliminate arcing occurrence in the systems. To eliminate arcing, one alternative is to electronically terminate the power supply to the system prior to the physical disconnection. The integrated MEMS force sensor on the power disconnect will be activated as a service technician disconnects the connector. The power supply to the system will be electronically shut off to prevent arcing during the physical interruption. The MEMS force sensor on the disconnect has an overall dimension of 3600 μm × 1000 μm × 10 μm and is fabricated with the Micragem fabrication process. A displacement reduction mechanism is incorporated into the sensor design to increase the sensitivity of the force sensor. Results show that the sensor is capable of measuring a maximum force input of 10.7 mN, resulting from a 20-μm displacement on the sensing structure.