Miniature fiber optic acoustic pressure sensors with air-backed graphene diaphragms
Douglas A. Olson, Haijun H. Liu, Zhijian Zhang, Yongyao Chen, Wen Zhongshan, Yu Miao, Hyungdae Bae, Qian Dong
We present a miniature graphene-based acoustic sensor utilizing a graphene-silver composite diaphragm covered on top of a UV-molded cavity that is directly fabricated on the tip of an optical fiber. The composite diaphragm consists of a 4-monolayer thick graphene film coated with a 5 nm thick silver layer. This unique diaphragm design can not only take the advantage of graphenes superior mechanical properties for simultaneously achieving high mechanical sensitivity and large bandwidth, but can also help improve the graphenes low optical reflectivity, rendering improved sensor sensitivity. Experimental results show that compared with a sensor with pure graphene diaphragm, using the graphene-silver composite diaphragm can enhance the sensitivity by three-fold, from 21.3 mV/Pa to 68.3 mV/Pa. The sensor with the composite diaphragm exhibits a large natural frequency of 20 kHz and a large damping ratio of 0.79, both of which ensure a large bandwidth.
Journal of Vibration and Acoustics-Transactions of the ASME
, Liu, H.
, Zhang, Z.
, Chen, Y.
, Zhongshan, W.
, Miao, Y.
, Bae, H.
and Dong, Q.
Miniature fiber optic acoustic pressure sensors with air-backed graphene diaphragms, Journal of Vibration and Acoustics-Transactions of the ASME, [online], https://doi.org/10.1115/1.4042929
(Accessed December 8, 2023)