Roll‐to‐Roll (R2R) Production of Large‐Area High‐Performance Piezoelectric Films Based on Vertically Aligned Nanocolumn Forests

The recent advances in flexible piezoelectric technologies have sparked a great interest in developing multifunctional next-generation transducers, which are in high demand for various challenging applications. Here, novel quasi 1-3 piezoelectric films with record-high piezoelectric voltage coefficients (g(33)), reaching up to 0.709 Vm N-1, approximate to 20% greater than the recently reported highestg(33)value in the literature, are reported. These composites are constructed via dielectrophoretic alignment of lead zirconate titanate (PZT) particles enhanced by graphene nanoplatelets, leading to densely structured cone-shaped nanocolumn forests in the thickness direction. To demonstrate its potential applications, both structured and randomly dispersed samples are characterized and used in various applications ranging from energy harvesting to structural and personal health monitoring. Furthermore, when placed on the sensor surface, the oriented piezoelectric films are shown to detect even the slight movements of a small-sized insect, demonstrating the ultrasensitivity of the system. Finally, to show the scalability of the dielectrophoretic process, a large area sample (12 ft long and 6-in.-wide) is also produced continuously via a novel multifunctional custom designed roll-to-roll manufacturing line. To the best of the knowledge, this is the largest single piece of piezoelectric film ever reported in the literature.