A Wide Temperature Range Weakly Coupled Resonant Micro-pressure Sensor

This paper for the first time reports the wide temperature range characteristics of a two-degree-of-freedom (2-DoF) weakly coupled micro-pressure sensor (100 similar to 1000Pa), and it was vacuum packaged by anodic bonding. Two fixed-fixed beam resonator gauges are designed to sense pressure differentially and they are weakly coupled by a slender mechanical beam. Both pressure and temperature can change the effective stiffness of resonators, thus the coupled resonators system will incur mode localization phenomenon. Because of temperature-induced axial package stress, the sensor's operating point will vary with temperature, so the coupled resonator amplitude exhibits turnover points. The results show that the sensor has a higher sensitivity (84800ppm) than the conventional frequency output sensor (1443.9ppm) within the linear range of -20 similar to 60 degrees C. The resolution reaches 1Pa and the hysteresis error is as low as 5% full scale and even 0.2% full scale at some temperatures within the linear range.