High thermal-stability Fabry-Perot acoustic sensor with graphene diaphragm

Although graphene-based Fabry-Perot (F-P) acoustic sensor demonstrates superior performance in terms of high sensitivity and compact size, temperature fluctuation remains a challenge affecting its cavity length and sensitivity. Here, a simple and portable graphene-based F-P acoustic sensor with quartz cavity structure (QCS) is developed to achieve a significantly decreased cavity length change of 3.1 nm/°C in the tested range of 20–80 °C, 95 times smaller than a referenced acoustic sensor with ceramic cavity structure (CCS). The sensitivity variation at typical 1 kHz is reduced to 0.46 %/°C, 2.3 times smaller than the result for the latter. Moreover, the maximum voltage sensitivity at 20 °C is up to 10.65 V/Pa@17 kHz in the range of 0.1–18 kHz, which is remarkably superior to the state-of-the-art F-P acoustic sensors reported previously. The device with temperature compensation exhibits potential for applications in aerospace and emergency rescue requiring weak acoustic detection in harsh environments.