Ultrathin-shell PVDF/CNT nanocomposite aligned hollow fibers as a sensor/actuator single element

Abstract

To facilitate a single element with the promoted dual sensing and actuation functionality, compared to the conventional individual sensors and actuators, different kinds of piezoelectric structures should be evaluated. Here, finite element method (FEM) simulations together with some aspects of the nanotechnology afforded an opportunity to simplify structure tailoring of the high performance sensor/actuator single element. First, we prepared ultrathin-shell poly (vinylidene fluoride) (PVDF) aligned hollow nanofibers. This geometrically confined nanostructure with low dielectric constant of ~3.6, efficiently increased strain, yielded to enlarge the piezoelectric voltage by ~250%, bending actuation by ~38%, and the β-phase content by ~18% when compared to the random solid nanofibers. Second, ~108% increase in sensitivity from 450 mV/N to 940 mV/N and ~21% increase in piezoelectric actuation from 14.8 μm to 18 μm obtained by addition of 0.05 wt% carbon nanotubes (CNTs) to PVDF aligned hollow nanofibers. Taking advantage of this hollow nanocomposite structure, ~45% improvement in crystallinity, ~263% enhancement in elastic modulus and complete removal of the nonpolar α-phase were occurred. The sensor/actuator single element would guarantee the adaptability, interconnectedness, and autonomy of the next generation robots, allow the size, weight, and cost of the system to be re-evaluated.