In traditional piezoelectric pressure sensor designs, the piezoelectric element is manufactured as a relatively simple shape such as a disc or plate that is subjected to a simple compressive or tensile load applied by the force collector, such as a diaphragm. In this study, a C-shape piezoelectric ring embedded in an epoxy matrix was analyzed for maximum deflection and electric potential output under hydrostatic pressure. Follow-up case studies of similar geometries such as piezoelectric plates and fibers embedded in epoxy matrix were also considered. In all cases, the polarization vector through the piezoelectric element was varied in order to increase the electric potential output while maintaining practical attainable polarization. The Finite Element Method (FEM) was utilized for the analysis and quantification of the different test cases. The location of electrodes for the sensor was chosen such that they could be used for both polarization and sensing. The study found that the utilization of piezoelectric materials of different shapes and geometries embedded in a polymer matrix for sensing applications has several advantages over thin plate solid piezoelectric structures. Initial results indicated an increase in electrical potential output by a factor of 20. The practical use of piezoelectric sensors embedded in epoxy matrix has been considered for measuring hydrostatic pressure in the knee cap where current techniques make use of a C-shape metallic element with a standard commercially off the shelf strain gauge.

Additional Metadata
Keywords Hydrostatic pressure, Piezoelectric sensors, Pressure sensors, Smart materials, Smart structures
Conference 21st International Conference on Adaptive Structures and Technologies 2010, ICAST 2010
Martinez, M, & Artemev, A. (2010). Piezoelectric sensing element for hydrostatic pressure measurements. Presented at the 21st International Conference on Adaptive Structures and Technologies 2010, ICAST 2010.