The Polymer Society of Korea

Abstract

Wearable devices enable real-time monitoring of various health indicators, supporting a healthier lifestyle.^[1,2] However, conventional wearable electronics face challenges such as skin irritation, low breathability, and performance degradation under mechanical deformation, limiting their use in humid environments.^[1,3] To resolve these problems, we propose a fiber-type synaptic memristive device featuring a methylammonium copper chloride and poly(vinylidene fluoride-co-hexa-fluoropropylene) (MA₂CuCl₄-PVDF–HFP) nanocomposite active layer on carbon nanotube (CNT) yarns. The device demonstrates stable memory and synaptic behaviors, with data retention for 10⁴ s and durability under 10⁴ pulses. Additionally, It operates reliably under physical deformations like bending radii (R) of 5 mm and 10 mm, and coiling in a glass tube (R = 4 mm) while maintaining water resistance after 1.5 hours underwater. These results provide a potential of flexible wearable smart systems.