Li, Cheng, Gao, Xiangyang, Guo, Tingting, Xiao, Jun, Fan, Shangchun, Jin, Wei
||Measurement Science and Technology, 2015, Vol.26 (8), pp.85101-85107
A miniature Fabry–Perot interferometric acoustic sensor with an ultra-high pressure sensitivity was constructed by using approximately 13 layers of graphene film as the diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule, which had an inner diameterof 125 μ m, and van der Waals interactions between the graphene diaphragm and its substrate created a low finesse Fabry–Perot interferometer with a cavity length of 98 μ m. Acoustic testing demonstrated a pressure-induced deflection of 2380 nm kPa−1and a noise equivalent acoustic signal level of ~2.7 mPa/Hz1/2 for a 3 dB bandwidth with a center frequency of 15 kHz. The sensor also exhibited a dynamic frequency response between 1 and 20 kHz, which conformed well to the result obtained by a... referencemicrophone. The use of a suspended graphene diaphragm has potential applications in highly sensitive pressure/acoustic sensors.