This study aims to examine the dynamic response of a polyvinylidene fluoride (PVDF) piezoelectric sensor which is embedded into an aluminum coupon using ultrasonic additive manufacturing (UAM). Traditional manufacturing techniques used to attach smart materials to metals on the surface have drawbacks, including the potential of exposing the sensor to adverse environments or physical degradation during manufacture. UAM can avoid these issues by integrating solid-state metal joining with subtractive processes to enable the fabrication of smart structures. A commercial PVDF sensor is embedded in aluminum with a compression technique to provide frictional coupling between the sensor and the metallic matrix. The PVDF sensor’s frequency bandwidth and impact detection performance are evaluated by conducting cantilever and axial impact tests, as well as harmonic excitation tests with an electrodynamic shaker. Under axial loading, the embedded sensor displays high linearity with a sensitivity of 43.7 mV/N, whereas impact tests in the cantilever configuration exhibit a steady decay rate of 0.13%. Finally, bending tests show good agreement between theoretical and experimental natural frequencies with percentage errors under 6% in two different clamping positions, and correspond to the maximum voltage output obtained from the embedded PVDF sensor at resonance.

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.

SPIE Digital Library Proceedings

This paper compares the magnetostrictive properties of Metglas and Galfenol and investigates their potential as substrate materials for diaphragms to tune the performance of piezoelectric diaphragm pumps. These pumps are found in medical, automotive, and aerospace applications. Conventional diaphragm pumps consist of a vibrating diaphragm actuated by a piezoelectric wafer affixed to a rigid substrate; operating in bending mode, the diaphragm propels a specific volume of fluid across a defined space. Pump designs generally represent a trade-off between maximum output pressure and maximum flow rate. In this paper, we propose two well-established magnetostrictive materials, Metglas and Galfenol, as alternatives to conventional passive substrates to actively modulate pump characteristics such as pressure and flow rate. We experimentally characterize the Delta-E effects of Metglas and Galfenol to verify their stiffness tunability in response to magnetic fields. We develop COMSOL finite element models to simulate the performance of a commercial piezoelectric pump with and without the addition of active substrate materials. Finally, we investigate the potential for tuning the performance of diaphragm pumps with magnetostrictive substrates. This concept can enhance the efficiency of pumping mechanisms, allowing for adaptable performance across a range of specifications.