Kevlar-reinforced hydrogel composites with enhanced puncture resistance, strain-sensing, and anti-freezing performance for flexible personal protective equipment

Abstract

A multifunctional composite that can withstand puncture threats and endure extreme environmental conditions is pivotal for next-generation personal protective equipment (PPE). Herein, we report a flexible Kevlar-reinforced hydrogel composite that simultaneously exhibits outstanding puncture resistance, strain-sensing functionality, and anti-freezing performance. The PVA hydrogel matrix, structurally enhanced via immersion in Na 3 Cit and Al 2 (SO 4 ) 3 dual-salt solution, demonstrates excellent mechanical robustness and strain-resistance responsiveness across both ambient and subzero environments. Integrated with Kevlar fabric, the flexible composite achieves a maximum quasi-static and dynamic puncture force of 69.55 N and 318.70 N, representing 4.07-fold and 3.09-fold improvements, respectively, over the neat fabric, and absorbs 94.58% of the impact energy from a drop hammer. Notably, the composite maintains superior puncture resistance (maximum quasi-static and dynamic puncture force of 55.97 N and 265.58 N) and flexibility (bending stiffness of 7.78 mN·cm) at -15 °C. Its strain-sensing capabilities remain sensitive and stable, offering excellent linearity, a broad detection range, and consistent performance over 500 cycles at both 25 °C and -15 °C, enabling real-time, reliable monitoring of human motion across diverse environmental conditions. This work offers a scalable and practical approach toward fabricating high-performance, all-weather flexible PPE for protective and wearable sensing applications in harsh environments.