MEMS Acoustic Emission Sensors

Direction Finding Using Multiple Mems Acoustic Sensors

Lead-free acoustic emission sensors.

Acoustic emission (AE) sensors have been fabricated using both soft- and hard-type lead-free (Na0.5K0.5)NbO3-based ceramics. The acoustic and electromechanical properties of the ceramics have been determined using the resonance technique. The lead-free AE sensors were calibrated using a laser source and compared to a commercial sensor. A lead zirconate titanate (PZT) 5H ceramics AE sensor has a...

Resonant capacitive MEMS acoustic emission transducers

We describe resonant capacitive MEMS transducers developed for use as acoustic emission detectors, fabricated in the commercial three-layer polysilicon surface micromachining process (MUMPs). The 1-cm square device contains six independent transducers in the frequency range between 100 kHz and 500 kHz, and a seventh transducer at 1 MHz. Each transducer is a parallel plate capacitor with one pla...

Modelling of Resonance Frequency of MEMS Corrugated Diaphragm for Capacitive Acoustic Sensors (TECHNICAL NOTE)

In this paper, a new model for resonance frequency of clamped circular corrugated diaphragm has been presented. First, an analytical analyzes has been carried out to derive mathematic expressions for mechanical sensitivity of diaphragm with residual stress. Next by using Rayleigh's method we present mathematical model to calculate the resonance frequency of corrugated diaphragm and investigate ...

Bar-Wave Calibration of Acoustic Emission Sensors

This study extended a bar-wave calibration method for acoustic emission (AE) sensors. It combined laser interferometer displacement measurements and the wave propagation medium of a long bar, excited at its end with an ultrasonic transducer driven by a pulser. Receiving bar-wave sensitivities of 16 types of AE sensors were measured and compared to their receiving sensitivities to normally incid...