FIG. 5.

Electroconductive fibers. (a) a snapshot of knotted core/sheath microfiber made of PVDF-HFP-TFE shell and liquid metal core (left) and its conductance stability in mechanical deformation up to ∼700% stretchability (right). Reproduced with permission from Zheng et al., Sci. Adv. 7, eabg4041 (2021). Copyright 2021 American Association for the Advancement of Science.⁵³ (b) Optical image of electrospun substrate with gold deposited electrodes. Scale bar, 2 mm. (c) Field potentials of cardiomyocytes using electrospun fibrous electrodes coated with a thin film of gold. (b) and (c) Reproduced with permission from Lee et al., Nat. Nanotechnol. 14, 156 (2019). Copyright 2019 Springer Nature.⁹⁶ (d) SEM cross-sectional image of a conductive, stretchable fiber, made with a butanol-based material. (e) The endurance of cyclic stretching for a conductive fiber (black) and a conductive fiber encapsulated with a tough self-healing polymer (blue). (d) and (e) Reproduced with permission from Kwon et al., Adv. Funct. Mater. 30, 2005447 (2020). Copyright 2019 John Wiley and Sons.¹⁰⁰ (f) Au nanowire fibers fabricated by wet spinning. (g) Stress-strain curve exhibiting the effect of nanowire alignments on the mechanical strength of the fiber. (f) and (g) Reproduced with permission from Reiser et al., ACS Nano 11, 4934 (2017). Copyright 2017 American Chemical Society.¹⁰⁸ (h) Cross section of a PEDOT:PSS/MXene fibrous composite. (i) Cyclic voltammetry (CV) profiles of MXene/PEDOT:PSS composite fibers, obtained at different operational potentials and a scanning rate of 5 mV s⁻¹. (h) and (i) Reproduced with permission from Zhang et al., Small 15, e1804732 (2019). Copyright 2019 John Wiley and Sons.¹⁰⁹ (j) SEM image of pure MXene fiber. (k) Comparison of electrical conductivity and Young's modulus of pure MXene fiber. (j) and (k) Reproduced with permission from Eom et al., Nat. Commun. 11, 2825 (2020). Copyright 2020 Authors, licensed under a Creative Commons Attribution (CC BY) license.⁶⁰ (l) SEM image of graphene fiber with nickel-cobalt phosphide nanosheet arrays, realized by solvothermal reaction in metal precursor solution. (m) Different pulse voltammetry responses of graphene fiber with nickel-cobalt phosphide nanosheet arrays with 100 μM dopamine (red) in the presence of 500 μM ascorbic acid (blue line), 500 μM ascorbic acid and 500 μM uric acid (green line), and 1.0 mM ascorbic acid, 1.0 mM uric acid and 1.0 mM glucose (purple line). (l) and (m) Reproduced with permission from Zhao et al., Biosens. Bioelectron. 205, 114095 (2022). Copyright 2022 Elsevier.¹¹⁰ (n) SEM snapshot of PEDOT:PSS fiber. (o) Maximum tensile strength of the PEDOT:PSS fibers and comparison with other fibers including graphene fibers. (n) and (o) Reproduced with permission from Zhang et al., J. Mater. Chem. A 7, 6401 (2019). Copyright 2019 Royal Society of Chemistry.¹¹⁴ (p) Transmission electron microscopy image of CNT fibers, exhibiting a good dispersion of CNT within the fiber. (q) The relationship between the resistance of a 3D-printed smart textile made from CNT fiber and its output short-circuit current and power density. (r) Measurements for the output short-circuit current generated by a grid line pattern on a textile as it comes into contact with or separates from a PET film at varying displacement speeds (5, 8, 10, 13, 15, and 18 cm s⁻¹). (p) and (q) Reproduced with permission from Zhang et al., Matter 1, 168 (2019). Copyright 2019 Elsevier.⁷⁴