A double cross-linked network structure hydrogel with CNF–C: Synergistically enhanced mechanical properties and sensitivity of flexible strain sensors

Abstract

The utilization of conductive hydrogels, particularly in the domain of wearable technology, has garnered substantial attention. However, the limited mechanical properties, low sensitivity, and lack of multifunctionality in conventional conductive hydrogels constrain their potential applications. Thus, the endeavor to develop conductive hydrogels with exceptional comprehensive performance remains a formidable challenge. In this investigation, chitosan quaternary ammonium salts and the conductive polymer poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) were employed as precursor materials, incorporating carboxylated cellulose nanofibers, to synthesize a novel double-crosslinked network hydrogel. The resulting hydrogel specimen exhibited noteworthy tensile strength (2.13 MPa), significantly enhanced elongation (547%), favorable strain sensitivity (Gauge Factor ranging from 0.91 to 9.78), and electrical self-healing capabilities. Additionally, it demonstrated accurate detection of subtle human movements and conversion of raw data into binary data. This research provides valuable insights into the advancement of conductive hydrogels for wearable soft electronics.