Fig. 1. Sensor principle structure diagram

Fig. 2. Diaphragm stress analysis diagram

Fig. 3. Process of MEMS diaphragm

Fig. 4. Silicon nitride diaphragm and sensor material. (a) Silicon nitride diaphragm; (b) sensor material

Fig. 5. Modal diagrams of two diaphragms. (a) 50 nm (2 mm×2 mm) diaphragm mode diagram; (b) 30 nm (1 mm×1 mm) diaphragm mode diagram

Fig. 6. Sensor spectra and space spectra. (a) Interference spectrum of 50 nm sensor; (b) space spectrum of 50 nm sensor; (c) interference spectrum of 30 nm sensor; (d) space spectrum of 30 nm sensor

Fig. 7. Sensor acoustic wave experimental device

Fig. 8. Sensor response signal in time domain and frequency domain. (a) Time domain signal comparison between the two sensors; (b) time and frequency spectra of 50 nm sensor; (c) time and frequency spectra of 30 nm sensor; (d) frequency domain response curves of two sensors

Fig. 9. SNR, MDP, and sound pressure response for two sensors. (a) SNR response; (b) MDP response; (c) sound pressure response comparison