Uniaxial Alignment of poly(vinylidenefluoride-co-trifluoroethylene) Nano Fibers for Ultra High Sensitive Pressure Sensor

Abstract

Organic ferroelectric materials have interested in flexible electronics because of their useful piezo- and pyroelectric response upon the applied pressure and temperature, respectively. Among the ferroelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers with trifluoroethylene (TrFE) exhibit excellent bistable polarization property which allowed us to apply various different types of flexible electronic devices such as non-destructive memory devices, energy harvesting cells and pressure sensors. Specifically for pressure sensor, PVDF-TrFE nano fiber structure shows advantage for more reliable sensing margin with promising endurance in the lab scale characterization than spin coated thin films. However, fabricating the PVDF-TrFE nano fiber remains as a challenging task. Here, we investigated highly aligned PVDF-TrFE array of nanofiber by using rotary jet spinning (RJS) method. The strong elongation force during the jet spinning process provides nano meter scale PVDF-TrFE fibers with global crystal orientation. As consequences a pressure sensor, our PVDF-TrFE nano fiber exhibited decent sensing margin in the bending test and achieved long endurance stability without further process.