Fig. 3: Sensing performance of the hyperpacked vibration sensor array.
From: Hyperpacked piezoelectric-powered capacitive sensor array for high-fidelity vibration detection
a, Schematic of the hyperpacked vibration sensor, highlighting the key parameters optimized in this study. b, Effects of the number of diaphragms, support thickness and diaphragm thickness on vibration sensitivity. Each dot represents the mean sensitivity calculated from 800 frequency-sweep points across the bandwidth of an independent sensor. Data are presented as mean ± s.d. (n = 4). c, Vibration sensitivity measured at 500, 1,000, 1,500 and 2,000 Hz under input amplitudes ranging from 0.1 to 2.5 g. The relationship between acceleration and output voltage was analysed using a linear regression model based on repeated measurements at four frequencies (n = 10 per frequency). The model exhibits strong linearity (R2 = 0.9867). d, Frequency response showing the effect of piezoelectric-induced charges on sensor performance, comparing diaphragms made of poled and unpoled PVDF-TrFE and SU-8. e, Limit of detection of the hyperpacked vibration sensor under a 500-Hz input. f, SNR of the hyperpacked vibration sensor under a 1-g input vibration at 500, 1,000, 1,500, 2,000 and 2,500 Hz.
