Fig. 4: Sensing performance of our sensor to high-frequency mechanical vibrations.

a Schematic of the wide-frequency mechanical stimuli detection and recording platform. b Capacitive response of the pressure sensor to the mechanical vibration at a fixed frequency of 12,500 Hz, showing the fast response time of our sensor. c The corresponding frequency spectra of the signals in (b). d Signal amplitude of the capacitive response to the vibration frequency from 200 Hz to 12,000 Hz between sensors with bonded (upper panel) and non-bonded (lower panel) interfaces. e Corresponding STFT spectrograms of (d). f Static pressure (~100 kPa) detection and vibrations detection with frequencies of 500, 4000, 8000, and 12,500 Hz under a static base pressure of ~100 kPa. g Vibrational signals with frequencies of 1000.0, 1000.2, 1000.4, and 1000.6 Hz were detected using the pressure sensor. h Frequency spectra of the signals in (g).