Photothermal Actuated Miniature Graphene Resonator for High-Sensitivity Pressure Detection

A miniature high-sensitivity Fabry-Perot (F-P) resonant pressure sensor was developed by transferring multilayer graphene (MLG) onto a copper mesh with a bore diameter of 20 μm. The resonance of the graphene membrane suspended and clamped on the copper mesh was opto-thermally excited and detected via optical fiber F-P interference. The measured resonant behaviors showed that the sensor achieved a maximum resonant frequency of 1.11 MHz with a good sensitivity of 10.4 kHz/kPa in the tested range of 0.01-50 kPa, which is much higher than that of common silicon resonant pressure sensor with a normal sensitivity of 0.1-0.4 kHz/kPa. Also, the output stability within 4200 s demonstrated an extremely low frequency deviation of 0.18% at 6 mW of optical power and 0.16% at 5 mW of optical power, thereby verifying a great potential in highly sensitive pressure measurement.