A fish-skin-inspired wearable scale-ionogel composite for impact protection and motion sensing

A bioinspired rigid-flexible composite with fish-skin architecture was developed. • Tough ionogel (25.85 MJ/m 3 ) with excellent environmental stability. • The composite exhibits a ballistic limit velocity (157.48 m s −1 ) and high specific energy dissipation (2.44 kJ/m). • Stable CNT conductive network enables sensitive, linear, and cyclic strain sensing. • Smart protectors integrate impact mitigation and real-time motion/impact monitoring. High-performance intelligent protective armor necessitates a synergistic combination of soft wearability, excellent impact resistance, and energy absorption capability. These requirements are becoming increasingly critical in modern society. Here, we report a rigid-flexible coupled bioinspired composite (APCIG-NCF) with a mechanically asymmetric architecture, which integrates impact mitigation and motion sensing. The composite adopts a hierarchical design in which an acrylic acid-based ionogel (APCIG) is covered by rigid nylon‑carbon fiber (NCF) scales. APCIG attenuates impact force and effectively absorbs impact energy through its high toughness (25.85 MJ/m 3 ) and reversible energy dissipation mechanisms. Moreover, owing to the rigid NCF, APCIG-NCF exhibits strong resistance to localized subsonic projectile impact, with a limit penetration velocity of up to 157.48 m s −1 . Additionally, carbon nanotubes inside APCIG establish a stable conductive network, enabling remarkable strain-sensing performance with excellent linearity and outstanding cyclic stability. Leveraging these properties, intelligent knee and elbow protectors were fabricated, achieving superior anti-impact performance and in situ monitoring. This work provides a new design strategy and material platform for the development of next-generation smart wearable protective gear.