Bioinspired Crystallization Refinement Strategy Enables Ion-Conductive Elastomers with an Ultra-Wide Strain-Insensitive Window for Reliable Signal Transmission and Adaptive Sensing

Abstract

Maintaining signal reliability under various strains is crucial for soft materials, but achieving strain-insensitive characteristics under high stretchability remains challenging. Here, we establish a crystallization-mediated regulation framework to achieve intrinsically strain-insensitive ion-conductive elastomers. Inspired by biomineralization, nanocellulose was introduced to regulate the crystallization of polycation chains to construct a continuous ion transport channel that is not affected by strain. The prepared ion-conductive elastomer (PUPD-0.50) has a strain-insensitive signal transmission fidelity window of up to 1100%, attributed to the “rigid-soft” conductive network containing refined crystal domains. Even at 1200% strain, the gauge factor (GF) value is as low as 0.12. Meanwhile, it exhibits ultrahigh stretchability (1256%), high toughness (17.16 MJ/m³), high ionic conductivity (1.22×10-2 S/m), and antibacterial properties. Additionally, its sensing applications in both contact and non-contact modes are successfully validated. The sensor can quickly output voltage signals by sensing the human electric field, with a response/recovery time as low as 60 ms. Remarkably, the output signal strength and response rate remain stable even under 500% strain, so it can stably transmit encrypted signals. This study provides an effective route to stabilize ionic transport, establishing a generalizable design paradigm for strain-insensitive ionic conductors in flexible electronics and human-machine interfaces.