Characterization of a PVDF sensor embedded in a metal structure using ultrasonic additive manufacturing

摘要

This paper investigates the characterization and functional performance of a piezoelectric polyvinylidene fluoride (PVDF) sensor embedded into an aluminum plate using ultrasonic additive manufacturing (UAM). While conventional manufacturing techniques such as non-resin-based powder metallurgy are being used to surface-mount smart materials to metals, they pose their own set of problems. Standard manufacturing approaches can physically damage the sensor or deteriorate electrochemical properties of the active material due to high processing temperatures or long adhesive settling times. In contrast, UAM integrates solid-state metal joining with subtractive processes to enable the fabrication of smart structures by embedding sensors, actuators, and electronics in metal-matrices without thermal loading. In this paper, a commercial PVDF sensor is embedded in aluminum with a pre-compression to provide frictional coupling between the sensor and the metal-matrix, thus eliminating the need for adhesives. Axial impact and bending (shaker) tests are conducted on the specimen to characterize the PVDF sensor’s frequency bandwidth and impact detection performance. Metal-matrices with active components have been under investigation to functionalize metals for various applications including aerospace, automotive, and biomedical. UAM embedment of sensors in metals enables functionalization of structures for measurement of stresses and temperature within the structure while also serving to shield smart components from environmental hazards. This technique can serve a wide-range of applications including robotics and tactile sensing, energy harvesting, and structural health monitoring.