Ultra-Sensitive Dual-Resonator Graphene Pressure Sensor with Temperature Self-Compensation

Silicon resonator sensors have limitations in detecting small pressure changes due to their structural dimensions. Graphene nanomechanical resonators, with their ultra-small thickness and excellent mechanical properties, offer the opportunity to break this limitation. Here, a highly sensitive graphene nanomechanical pressure sensor with integrated temperature self-compensation is reported. It consists of two vacuum anode-bonded graphene resonators: one is sensitive to pressure and temperature while the other to temperature only, allowing for the cancellation of thermal effects via detecting the difference in the resonant frequencies. A sensitivity of 24.1 kHz kPa^-1 is achieved over the pressure range of 0.001 to 500 kPa, 68 times higher than the state-of-the-art silicon pressure sensors. The full-scale (FS) hysteresis error is 0.31% with a repeatability of 0.75% in three forward and reverse stroke pressure tests. Within the temperature range of -40 to 120 °C and the pressure range of 0.001 to 500 kPa, the maximum pressure error is 6.51 kPa, giving an accuracy of 1.302% FS. The high performance of the device makes it promising for applications in aerospace, automotive, and healthcare industries as well as other fields requiring high-sensitivity pressure measurements.