Coaxially oriented PVDF/MWCNT nanofibers as a high‐performance piezoelectric actuator

Abstract Controlling the orientation of the carbon nanotubes inside a polymer matrix essentially improves their reinforcement effect even at small loading levels, which is attractive from the processing point of view. We inform the utilization of electrospinning to produce highly aligned small‐diameter polyvinylidene fluoride (PVDF) nanofibers where the multiwalled carbon nanotube (MWCNT) are coaxially aligned inside the PVDF nanofibers. The coaxially aligned MWCNTs arrange large numbers of contact sites with the polymer chains, thereby providing enhanced interfacial interactions, resulting in the superior effect of the MWCNTs on the crystalline structure and actuator response of the PVDF at low loading levels (0.06 wt.%). An effective α‐ to β‐phase conversion occurred through the synergistic effects of the electrospinning and MWCNTs, the β‐phase content reached 94%. Also, the degree of crystallinity increased up to 50% respecting the pure nanofibers. The bending actuation of the nanofibers was analyzed as the active layer of soft piezoelectric actuators in a unimorph configuration. The well‐aligned nanofibers showed better actuator deflection than the randomly oriented nanofibers. Comparing the PVDF nanofiber‐based actuators in the literature, our actuators exhibited excellent piezoelectric performance with high potential for practical applications. Highlights Highly aligned small‐diameter PVDF/CNT nanofibers produced by electrospinning. Axially aligned CNTs induce a great piezoelectric effect at low‐loading levels. The F (β) was 94%, and the crystallinity increased by 50% at only 0.06 wt% CNTs. Well‐aligned nanofibers showed better actuator response than the random ones. The soft actuators showed a higher performance than those in the literature.