Fabrication Technique for Microelectromechanical systems Piezoelectric Sensor The MEMS based piezoelectric sensor consists of piezoelectric  diaphragm, cavity and microtunnel structure in silicon substrate, and Pyrex glass for sealing. For monitoring high sound pressure levels, the sensor is employed in  aeroacoustics applications. High sound pressure levels (120 dB), are primarily measured by the sensor. This sensor uses commercially available piezoelectric material  which is sandwiched between two metal electrodes. Dicing of this commercially available piezoelectric material is done according to device dimension. Bulk  micromachining techniques are used to fabricate cavity and microtunnel structure in silicon substrate. The silicon substrate has through-hole cavity with embedded  microtunnel. The sensor is sealed from backside with the help of Pyrex glass using anodic bonding technique. In the present invention, technique for fabrication of  MEMS piezoelectric sensor has been developed. The diced piezoelectric diaphragm is positioned on top of the fabricated silicon structure. To meet the requirements of  testing and applications, the fabricated chip is mounted on a package. For sensor protection and in accordance with the experimental setup, a stainless-steel cover is  used. Due to the proposed technique, numbers of fabrication steps are reduced than the previously reported acoustic sensors. The sensor's linear operational region has  significantly increased in comparison to previously reported acoustic sensors, which have a cavity and microtunnel structure. Due to simplified fabrication process, the  invented technique will be cost-effective and promises a broad dynamic range of operation for high sound pressure level applications.Fig: 1 and 2