Stable and Corrosion-Resistant Sapphire Capacitive Pressure Sensor for High Temperature and Harsh Environments

Abstract

This paper describes a capacitive pressure sensor utilizing sapphire as a structural material with a novel sapphire micromachining technology. It features high corrosion resistance, an oil-free structure, and high temperature usage. The fabricated sensor is confirmed to be a high accuracy pressure sensor having high pressure sensitivity in the temperature range covering from room temperature to 250°C with small thermal zero shift. The sensor is an absolute pressure sensor which is designed for a range of 0–350 k Pa. A thermal pressure sensitivity shift of a 0.03 % of full scale per degree (%F.S./°C) and a thermal zero shift of a 0.02 %F.S./°C are obtained.