A rationally designed flexible self-healing system with a high performance supercapacitor for powering an integrated multifunctional sensor

Abstract

We report on the fabrication of a rationally designed self-healing and flexible all-in-one system. Using a vacuum filtration method, an integrated system consisting of a planar supercapacitor and a multifunctional sensor is fabricated with gold nanosheet (AuNS) interconnections. A fast and reversible self-healing hydrogel based on the diol-ester bonding between poly(vinyl alcohol) (PVA) and borax is synthesized, and its mechanical stability is enhanced with the additional hydrogen bonding between PVA and agarose. Using an electrolyte of PVA/borax/agarose/NaNO3 and an electrode consisting of multiwalled carbon nanotubes (MWCNTs) coated on an AuNS current collector, a high-performance self-healing flexible planar supercapacitor is fabricated. The multi-functional sensor is made of MWCNTs with a zinc oxide nanowire composite. Both the supercapacitor and sensor recover their performance from bisectional damage via physical contact with a water supply. The self-healing supercapacitor shows mechanical stability for bending deformation even after repetitive self-healing cycles. Furthermore, the integrated system exhibits self-healing performance through stable sensing of NO2 gas and UV light using the stored energy in the supercapacitor after recovery from repetitive bisection of the sensor. This work demonstrates the high potential of our rationally designed flexible self-healing all-in-one system in high-performance wearable devices with high durability and longevity.