UIC-2014-160 – A novel, compact, low cost MEMS based acoustic emission sensors

The effective implementation of an acoustic emission (AE) method to detect and locate active flaws depends on the performance of the transducer selected. Conventional piezo electric ceramics cannot be physically used to design miniature low-frequency (less than 100 kHz) AE transducers. Furthermore, considering the cost of piezoelectric AE transducers, monitoring large areas with ubiquitously spaced transducers becomes prohibitively expensive. Investigators at UIC have developed micro-electro-mechanical systems (MEMS) acoustic emission (AE) transducers that are manufactured using an electroplating technique. The transducers use capacitance change as their transduction principle. The researchers have demonstrated that these sensors have comparable sensitivity, a much smaller footprint and a much lower cost over existing piezoelectric sensors. The comparison of the MEMS transducers with similar frequency piezoelectric transducers shows that the MEMS AE transducers have better response characteristics and sensitivity at the resonance frequency and well-defined waveform signatures (rise time and decay time) due to pure resonance behavior in the out-of-plane direction. Mark Krivchenia krivchen@otm.uic.edu (312) 996-6626