Multifunctional and Flexible Polymeric Nanocomposite Films with Improved Ferroelectric and Piezoelectric Properties for Energy Generation Devices

Conventional ceramic based piezoelectric materials are brittle, which restricts their use in energy harvesting where flexibility is required. Polymer counterparts are flexible but exhibit comparatively reduced electrical output. Here, we provide a method that overcomes these challenges through design of composites comprised of a piezoelectric polymer matrix (PVDF-TrFE) and filler nanoparticles (niobium-doped Pb(Zr,Ti)O3). Nanoparticles were functionalized with trimethoxysilylpropyl methacrylate (TMSPM) that promotes linkage between filler and the matrix to achieve effective local dipole–dipole interaction. An enhanced remnant polarization of 9.1 μC/cm2 at 100 Hz and high longitudinal piezoelectric coefficient of 101 pm/V are obtained. Using this composite, a piezoelectric nanogenerator (PENG) is demonstrated that delivers an output of 10 V in response to mechanical bending. Our composite devices show an output which is greater than 200% in comparison to polymeric PVDF-TrFE film based devices. These composites were also implemented in a triboelectric nanogenerator (TENG) device that can power 10 commercial red LEDs. This novel hybrid piezoelectric and triboelectric nanogenerator device has promise for powering wireless sensor nodes and wearable medical devices.