Robust and tunable hydrogels strengthened by dynamic amphiphilic ionic domains

Abstract

Hydrogels have gained increasing attentions in wearable electronics, but endure notch-sensitive and poor mechanical behavior in real-world applications. Herein, a robust and tunable hydrogel network was constructed by involving a polymerizable amphiphilic ionic liquid in polymer chains through a facile and novel strategy without additional chemical crosslinkers. The ingeniously designed dynamic amphiphilic ionic domains that are tuned by the structural domain and functional domain are crucial for reinforcing the structural integrity and allowing the polymer chains to accomplish reversible unfolding and ordered migration. The robust and functional microstructures effectively prevent crack propagation, enhancing the fracture strain (1200–2390%), tensile stress (380–1560 kPa), toughness (5–15 MJ m−3), and conductivity (0.13–0.2 mS cm−1). The obtained hydrogel acts as an excellent mechanoresponsive sensor to perceive various external stimuli to sensitively detect diverse human activities including large body motions and subtle muscle movements via electrical signals. Additionally, this strategy shows good applicable potential for preparing high-performance hydrogels based on monomers containing active double bonds, overcoming the disadvantages of poor mechanical properties of traditional free radical polymerization gels. It is anticipated that the design of dynamic amphiphilic ionic domains will provide guidance for regulating the polymer network of hydrogels and show great application potentials in real-life scenarios.