Effect of PVDF Concentration and Number of Fiber Lines on Piezoelectric Properties of Polymeric PVDF Biosensors

Poly(vinylidene fluoride) (PVDF) fiber biosensors are prepared by a near-field electrospinning (NFES) to evaluate the effect of PVDF concentration (16–20 wt%) and number of fiber lines (10-90) on the sensitivity of PVDF sensors. Among various PVDF fiber arrays consisting of 50 lines, the highest peak voltage of 132.0±8.3 mV is observed for the 18 wt% PVDF sensor due to the formation of straight-line-shape fibers. A beads-on-string fibers are observed for the PVDF fibers containing more than 18 wt%. The voltage increases linearly with increasing the number of PVDF fiber lines from 10 to 90. The spectral results of the sensors exhibit the same signal generated by natural frequency of Al cantilever. An equivalent RC circuit model, consisting of two resistors and one capacitance, is incorporated to describe the piezoelectric behavior of PVDF sensors. Simulation results are consistent with the cantilever test results and no cytotoxicity is observed, implying that the sensitivity of PVDF biosensor is mainly governed by PVDF concentration and number of PVDF fiber lines.