lightweight, portable, foldable, stretchable, and biocompatible are triggering the intense interests of researchers from multidisciplinary fields like biology, material science, and chemistry. [9][10][11] Nowadays, great attempts have been devoted to developing advanced flexible electronics by integrating various inorganic or organic traditional conductive functional materials with flexible electrochemically non-active elastic substrates. [12][13][14][15][16][17] Generally, traditional conductive functional materials encounter the shortcomings such as high price, inherent rigidity, weak biocompatibility, poor mechanical, and inferior interface bonding properties, which are employed to evaluate the performance of the flexible electronics materials. Therefore, pursuing these materials with practical applications is an emergent issue in the research field.Nevertheless, in numerous conductive functional materials, hydrogels with 3D network structures have been largely selected as the excellent candidates due to their high water content, excellent biocompatibility and biodegradability properties, high elasticity, and outstanding stimulus responsiveness. [18][19][20][21][22][23] Conductive hydrogels are generally constructed via integrating various conductive substances into the hydrogel matrix, which are comprised of carbon materials (carbon nanotubes (CNTs), graphite), metal oxides, metal sulfides, metal nanoparticles and conductive polymers (polyaniline (PANI), polypyrrole (PPy), poly (3,4-ethylenedioxythiophene) (PEDOT:PSS)). [24][25][26][27][28][29][30] For example, Han et al. fabricated a CNTs-based conductive hydrogel for strain sensors by in situ polymerization of acrylic acid and acrylamide in water/glycerol solutions in the presence of polydopamine-decorated CNTs. [28] Devaki et al. reported a 3D Ag nanoparticles-polyacrylic acid conductive hydrogel via combining in situ polymerization of acrylic acid and reduction of Ag + . [29] Duan et al. constructed a robust and force-sensitive conductive hydrogel employing synthesizing polyacrylamide and PANI in closely packed swollen chitosan microspheres. [30] According to the different configurations of hydrogels, conductive hydrogels are allowed to be processed into 3D bulk gels, 2D gel films, 1D gel fibers, and 0D microgels. [31][32][33][34][35][36] The mechanical flexibility of 1D fibrous configuration is superior to that of 3D bulk or 2D film configuration due to its well-oriented polymer chains, light weight, and low dimensions for flexible electronics. Moreover, ultra-flexible fibrous materials can be easily woven into diverse soft and breathable fabrics, which
