▎ 摘　　要

Fibrous wearable electronics have attracted extensive attention owing to their lightness and flexibility. However, they face challenges to work synergically with conductive components when stable performance and multi-function are required simultaneously. Here, plant-extracted 3D porous Juncus effusus (JE) fiber decorated with conductive graphene/polypyrrole (G-PPy) yields flexible smart fibers (G-PPy-JE) with integration of Joule heating and strain sensing properties. G-PPy-JE fibers were prepared by hierarchically anchoring the graphene sheets and PPy to 3D JE microfibrils via a facile dip coating and in-situ polymerization method. Synergistic effects in the hybrid architecture contribute to a highest conductivity of G-PPy-JE (96.85 S m-1) compared to pristine JE, G-JE, and PPy-JE. On the one hand, G-PPy-JE fibers showed a great electric-thermal property, which achieved a temperature of 147 degrees C at 10 V within 10 s. The good Joule heating performance maintained when weaving these fibers into fabrics as thermal therapy clothing. On the other hand, G-PPy-JE fibers after encap-sulation can serve as a strain sensor with a high sensitivity (GF of 7.36-11.36), great stability (10-100 %), and good durability over 500 cycles. The strain sensor also reflected capabilities to detect a full range of human motions. This work paves a way for manufacturing cost-effective, green, and versatile fibrous electronics for promising wearable application.