Adam Kovacs, “PVDF-Based Smart material for Sensing and Actuation”
Mentor: Chiu Law, Electrical Engineering, Engineering & Applied Science (College of)
Poster #179
Piezoelectric-based smart materials can be engineered to sense mechanical strain or be actuated by electrical energy. Traditionally, ceramic piezoelectric materials are common in micro-positioning devices with precise motion control. This project proposes to achieve precise motion control with a Polyvinylidene fluoride (PVDF) polymer that is flexible and operates under higher strains than ceramic materials. The first phase is to determine the piezoelectric coefficient of the PVDF polymer by measuring the voltage across the thickness of a PVDF workpiece with double sided aluminum lamination while the workpiece is stressed along its long axis with a tensile tester following the ASTM D638 standard. Since the coefficient is the ratio of the electric field to the tensile stress, experimental readings along with workpiece thickness will be sufficient for its estimation. With the value of the coefficient determined, a sensing structure will be designed so that it can be easily integrated with the PVDF polymer and the voltage across the smart metamaterial structure, reflecting the magnitude of the displacement. This voltage will be filtered, amplified and fed back to the actuator that sets positions or progressive motion. So far, the tensile testing setup was established for a PVDF workpiece fabricated according to the ASTM standard. With the experimental data from the tensile testing, the piezoelectric coefficient was verified, and compared to ones found in related scientific literature. The next phase of this project is to prototype a sensing structure for the polymer, a critical step toward realizing a functional smart metamaterial-based actuation system.