Scaffold-microenvironment decoupling in chitosan hydrogels: A design strategy for integrated energy storage, sensing, and energy harvesting

Abstract

Chitosan-based hydrogels are attractive for sustainable flexible electronics, yet their development is fundamentally hampered by a persistent materials dilemma in which enhancing mechanical integrity through crosslinking or crystallization inevitably sacrifices ionic mobility and environmental stability, leading to poor conductivity and dehydration susceptibility. To address this dilemma, we present a scaffold-microenvironment decoupling strategy. This approach architecturally separates the requirements for mechanical robustness and ion transport by constructing a hierarchically tough yet open polymer scaffold, while independently programming the internal aqueous phase into a highly conductive and cryo-tolerant microenvironment through tailored ion hydration and salting-out. The resulting hydrogel materializes this synergy, exhibiting integrated properties including high mechanical strength, ultra-high ionic conductivity of 68.6 mS/cm, and exceptional resistance to freezing below −85 °C and dehydration. Beyond a multifunctional material, this system validates a novel design paradigm. Its practical efficacy is demonstrated across three distinct and demanding electronic applications serving as an ultra-stable electrolyte for flexible supercapacitors with over 10,000-cycle durability, a high-fidelity wearable sensor for physiological signal monitoring, and an effective component in triboelectric nanogenerators. This work provides a blueprint for designing next-generation sustainable soft materials where traditionally conflicting properties can be harmoniously unified.

Keywords

Chitosan hydrogel / Scaffold-microenvironment decoupling / Flexible electronics / Gel electrolyte / Strain sensor

References

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