Dynamic and Stationary Performance Analysis of Diaphragm Based Acoustic Pressure Sensor
Vasudha Hegde1, Siva S Yellampalli2, H M Ravikumar3

1Vasudha Hegde*, Department of Electrical and Electronics Engineering, Nitte Meenakshi Institute of Technology, Bangalore-64, India.
2Dr. Sva S Yellampalli, Professor, UTL Technologies Ltd, Bangalore-22. India.
3Dr. H M Ravikumar, Professor, Department of Electrical and Electronics Engineering, Nitte Meenakshi Institute of Technology, Bangalore-64, India.
Manuscript received on July 30, 2019. | Revised Manuscript received on August 25, 2019. | Manuscript published on August 30, 2019. | PP: 4108-4115 | Volume-8 Issue-6, August 2019. | Retrieval Number: F9262088619/2019©BEIESP | DOI: 10.35940/ijeat.F9262.088619
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Pressure sensing and measurement are of utmost importance in many of the process industries and biomedical applications. The key element of the pressure sensor is diaphragm and the diaphragm design including shape and dimensions play a major role in sensitivity of pressure sensor irrespective of the type of sensor viz. capacitive, piezoresistive or piezoelectric sensor. The acoustic pressure sensors require the proper analysis of dynamic performance of the key element since the acoustic source is dynamic pressure. This paper presents the stationary and dynamic performance analysis of diaphragm for piezoelectric acoustic pressure sensor. The analysis has been done for better deflection of the diaphragm and optimized stress and strain in order to achieve maximum sensitivity. In design step, at first the diaphragm is analysed for natural frequency, modal frequencies and bandwidth of the structure since the piezoelectric resonant sensors can be used for sensing whenresonant frequency of the membrane is at least 3 to 5 times the highest applied frequency and for energy harvesting applications, when it is almost equal to the applied frequency.Hence, a comparison of shapes of diaphragm, with their fundamental and modal frequencies, deflection, and stress and strain is established. Further a resonant sensor structure is also analyzed for dynamic performance with cavity neck of different size to understand the importance of cavity neck in dynamic performance of the sensor. The circular diaphragm is found be the best choice from the point of view of maximum deflection and natural frequency and the structure with cavity neck has better bandwidth and deflection. 
Keywords: Acoustic Sensor, Diaphragm Based, Natural Frequency, Piezoelectric.