Self-powered high signal-to-noise ratio acoustic emission sensor and its demonstration on detecting dynamic friction variation

This paper presents a micromachined self-powered acoustic emission (AE) sensor based on a novel corrugated PVDF sensing core. The developed transducer exhibits superior signal-to-noise ratio (SNR) and is much higher than current commercial AE sensor based on the same steel-ball drop test experiment. The sensor is applied to monitor identical ball-bearings with different levels of wear. Through short-time Fourier transform, frequency-domain spectrum and wavelet analysis, results demonstrate its capability of detecting dynamic friction effectively. This can be very useful in monitoring the health condition of moving components and predicting possible failures in advance.