In-Plane-Stress-Type Vapor Sensor with Higher Q Factor Based on Independent Vibration of SI Resonator

To improve the sensitivity of gas detection stress sensors based on polymer swelling, we developed an in-plane stress sensor in which the silicon resonator can vibrate independently at its resonant frequency. The vibration of the resonator improved the Q factor of 3.4 times more compared to the vibration in unison. Rate of the resonance frequency change in response to water exceeded those of previous studies, and detection at the ppm level was possible for some types of gases.