Fabrication and Characterization of a Flexible PVDF Fiber-based Polymer Composite for High-performance Energy Harvesting Devices

A flexible polyvinylidene fluoride (PVDF)/polydimethylsiloxane (PDMS) composite prototype with high piezoelectricity and force sensitivity was constructed, and its huge potential for applications such as biomechanical energy harvesting, self-powered health mon- itoring system, and pressure sensors was proved. The crystallization, piezoelectric, and electrical properties of the composites were char-acterized using an X-ray diffraction (XRD) experiment and customized experimental setups. The composite can sustain up to 100%strain, which is a huge improvement over monolithic PVDF fibers and other PVDF-based composites in the literature. The Young’s modulus is 1.64 MPa, which is closely matched with the flexibility of the human skin, and shows the possibility for integrating PVDF/PDMS composites into wearable devices and implantable medical devices. The 300 µm thick composite has a 14% volume fractionof PVDF fibers and produces high piezoelectricity with piezoelectric charge constants d31 = 19 pC/N and d33 = 34 pC/N, and piezo-electric voltage constants g31 = 33.9 mV/N and g33 = 61.2 mV/N. Under a 10 Hz actuation, the output voltage was measured at 190 mVpp, which is the largest output signal generated from a PVDF fiber-based prototype.