Fabrication and characterization of polymeric three-axis thermal accelerometers

Abstract

The concept, fabrication process, and characterization of a three-axis thermal accelerometer are presented in this paper. A combination of microelectromechanical systems (MEMS) technology with microinjection molding enables the realization of functional, highly complex 3D geometries at the microscale, used here for the fabrication of a fully integrated three-axis accelerometer. While conventional thermal accelerometers are silicon based, using MEMS technologies only, the integration of polymeric materials and technologies into the fabrication process can greatly improve the realization of three-axis devices while diminishing the typical thermal losses. Three-axis thermal accelerometers were successfully fabricated by combining the proposed technologies proving the viability of the concept. Fabricated accelerometers show xy-axis sensitivity around 8 mV g(-1), a z-axis sensitivity of 2.2 mV g(-1) for a power of 45 mW and a 4 Hz bandwidth (bandwidth is based on simulations). Thermal tests performed showed that the heater can sustain up to 280 degrees C without overheating the remaining structures and damaging the device.