Modelling and experimental verification of a 350µm diameter PMUT operating in Isopropanol.

This paper outlines the design, construction and testing of a 350µm diameter Piezoelectric Micro Machined Transducer (PMUT). The PMUT was designed to operate in liquid Isopropanol as surrounding environment and had an air-filled cavity below the diaphragm. PMUT devices deployed in liquids and operating at higher frequencies such as in this case, where the PMUT would be operating at above 450kHz, have potential to be utilized to study concrete structures from within the pore structure itself. The design of the PMUT was conducted through a Finite Element Model (FEM) designed in the frequency domain. The masks for the PMUT designed through the FEM process were then created and the prototype device manufactured through the Piezomumps process. Finally, the actual PMUT was characterized through the use of laser vibrometer equipment. The results obtained from the actual device’s characterization process were then compared with the values obtained from the mathematical models.