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 CO 2 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.