图1、a) Scheme of the architecture of GO and dodecylamine, and the synthesis process for the functionalized GO. b) Illustration of the vibrating diaphragm with fixed edge for converting acoustic signal into light signal. c) Scheme of the structure and principle of the FP sensor.
图2、a) FTIR spectra of dodecylamine, GO, functionalized GO. b) Raman spectra of GO and functionalized GO. c,d) XPS spectra of GO (C1s, N1s). e,f) XPS spectra of functionalized GO (C1s, N1s).
图3、a) Scheme of preparing functionalized GO films using the self-assembly method. b) Scheme of the multi-layer functionalized GO film. c) Procedures of the preparation of multi-layer functionalized GO films and their subsequent transfer to the sensor probe. d) Microscopic image of the film on a silicon substrate. e) SEM image of the functionalized GO film.
图4、a) Scheme of the dual-wavelength phase demodulation system. b) Comparison of FP sensor and standard microphone at 20 Hz. c) Power spectrum of the demodulated phase signal. d) Sensitivity of the functionalized GO and GO-based FP sensors. e) Output of both the GO-based and functionalized GO sensors under 20 Hz acoustic signals. f) Sensor response to varying sound pressures at 10, 20, and 50 Hz. g) Linear correlation between phase signal output and sound pressure at 10, 20, and 50 Hz acoustic signals. h) Power spectra of 10, 20, and 50 Hz acoustic signals at sound pressures of 1.63, 1.84, and 1.66 Pa, respectively.
图5、a) Sensor response over 60 s. b) Power spectrum output with no signal. c) Power spectrum output with acoustic signal at 20 Hz. d) Typical frequency of demodulated phase signals in the range of 0.05–200 Hz (including 0.05, 0.1, 0.5, 1, 5, 10, 20, 50, 100, and 200 Hz), and e) The power spectrum of demodulated phase signals.
