Fabrication of Self-Healable, Low-Temperature-Resistant, Conductive Polyionic Gel Strain Sensors and Construction of Poly(ionic liquid)-Based Superhydrophobic Coating

Easy damage, inability to self-heal, and freeze hardening at low temperatures are still the main issues that limit the development of gel sensors. In this work, multifunctional polyionic composite gel strain sensors were fabricated by combining poly(vinyl alcohol) (PVA) with hydrophobic imidazolium-type poly(ionic liquid) (P[VPI⁺][Tf₂N^–]).

The mixed polymer solution realized spontaneous gelation at room temperature, and the gels exhibited self-healing, antifreezing, high stretchability, and conductivity, making them suitable for human joint motion monitoring and speech recognition at room or low temperatures. Moreover, through modification with silica nanoparticles and heptadecafluorodecyltrimethoxysilane, the nanocomposite coating of PVA/P[VPI⁺][Tf₂N^–] achieved superhydrophobicity (a static contact angle of 159.03°), displaying effective antifogging, antifouling, and self-cleaning properties.