High-resolution pressure sensor for photo acoustic gas detection

This paper presents a novel micromachined pressure sensor and its use in photo acoustic gas detection. The pressure sensor has a bossed membrane with two areas with different thicknesses, giving a resolution of 9 or 11 μV/V Pa, depending on the boss radius. At the same time, the burst pressure is above ±1 bar. Device fabrication and characterisation is presented, and the sensor is demonstrated to function in photo acoustic CO2 cells manufactured both by manual mounting and anodic bonding. The sensor is designed for a high volume commercial foundry process, and the bonded photo acoustic cells are suitable for large-scale production.