In this paper we present a simpler technique for designing an acoustic sensor based on Zinc Oxide as thin film for diaphragm. This diaphragm thickness has been optimized to withstand sound pressure level range of 100–200 dB. Stress distributions using Intellisuite has been plotted. We utilize MEMS technology to design acoustic displacement sensor chips on single crystalline silicon. A SiO 2 layer behaves as dielectric. The diaphragm exhibits excellent physical and chemical properties that include membrane forming ability, insensitive to the background pressure and good mechanical strength. The diaphragm shows relative change in displacement in response to different sound pressure level.