Zero temperature coefficient gas-sealed pressure sensor using mechanical temperature compensation

A novel gas sealed capacitive pressure sensor with a self-temperature compensated structure is reported. The pressure sensor is sealed by Au-Au diffusion bonding in nitrogen with a pressure of 100 kPa and integrated with a platinum resistor based temperature sensor for human activity monitoring. A ring-shaped structure on the diaphragm of the pressure sensor is used for temperature compensation. The pressure sensor with the temperature compensation structure can mechanically suppress the thermal expansion effect of the sealed gas in cavity. Using the compensation structure, measured temperature coefficient was much reduced as compared to that of the pressure sensor without compensation. The sensitivities of the pressure sensor before and after compensation are almost same in a pressure range from 80 kPa to 100 kPa.