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Zheng et al. Soft Sci. 2026, 6, 32 Page 9 of 57

orientation, despite the exceptionally high intrinsic conductivity of single-layer graphene (~10 S·m ).
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Significant progress has been made in addressing this through synergistic regulation using techniques
including chemical doping, efficient reduction, and structural optimization.

It is essential to establish effective seamlessly interconnected electronic channels. Grain boundaries and
electron scattering can be decreased by using large-sized GO precursors and producing well orientated
nanosheets. Tensile stress, for example, causes sheets to align axially during wet-spinning, and a 1.3 draw
ratio increases conductivity by 56% . Through extreme shear stress, technologies such as microfluidic
[12]
spinning achieve ultra-high sheet orientation [Figure 4A], producing fibers with conductivities as high as
1.04 × 10 S·m -1[16] . Additionally, a crucial stage in improving and restoring conductivity is reduction
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treatment. In order for GO to become conductive, its sp network structure must be restored by reduction.
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Chemical reduction techniques work in mild conditions, although they usually have limited structural defect
correction and conductivity of 10 -10 S·m . High-temperature thermal reduction (> 1,273 K) improves
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graphitization and allows for a more complete elimination of functional groups containing oxygen. Electrical
conductivities of up to 8 × 10 S·m are seen in fibers treated at 3,273 K . Qi et al. created GF fabrics with
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[17]
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porous architectures, superior conductivity, and flexibility at the fabric level by combining a
“plasticization-swelling” technique with comprehensive thermal reduction . A material basis for smart
[53]
textile integration is provided by the scanning electron microscope (SEM) image of the fiber cross-section
[Figure 4B].
Novel approaches to preparation have created new opportunities. By using polymeric carriers to electrospin
GO, Han et al. produced graphene nanofibers with diameters ranging from 100 to 900 nm . As seen in
[54]
Figure 4C, these fibers demonstrated electrical conductivities as high as 2.02 × 10 S·m after annealing at
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3,000 °C. Moreover, layer stacking problems are avoided when graphene coatings are grown in situ on fiber
substrates using chemical vapor deposition (CVD). As seen in Figure 4D and E , the resultant textiles have
[66]
exceptional electrothermal characteristics and tunable sheet resistance. One important tactic for getting over
the inherent conductivity limit is chemical doping. By adding high-concentration dopants like K, FeCl , and
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Br , Cao et al. greatly enhanced carrier concentration and boosted conductivity to the 10 S·m region .
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[69]
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Interestingly, K-doped fibers’ conductivity (2.24 × 10 S·m ) even outperformed metallic nickel. In order to
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improve interlayer forces and carrier concentration through N doping, Kim et al. used a bio-inspired
poly(dopamine) (PDA) modification and pyrolysis technique . As seen in Figure 4F, composite
[70]
architectures containing metals, such as silver nanowires (AgNWs), also successfully increased conductivity
and carrier capacity . Interestingly, calcium intercalation doping has shown promise for flexible
[49]
superconducting devices by inducing a superconducting transition (Tc ≈ 11 K) in macroscopic GFs for the
first time . For practical applications, the doped fibers’ environmental stability is still a problem.
[71]
The electrical properties of graphene-based soft conductive fibers have consistently outperformed those of
conventional carbon fibers (0.1-1.4 × 10 S·m ) and CNT fibers (~5 × 10 S·m ) through multidimensional
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synergistic optimization, providing a strong basis for their use in flexible electronics and smart textiles .
[72]
Thermal properties
Graphene is a perfect material for creating extremely thermally conductive fibers because of its exceptionally
high intrinsic thermal conductivity, which can reach up to 5,300 W·m ·K in a monolayer . However, weak
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[73]
interlayer tensions, grain boundaries, and defects seriously hinder phonon transport in macroscopic fibers,
resulting in a considerable drop in thermal conductivity as structural disorder increases . As a result, there
[74]
are two main approaches to thermal management research on graphene-based fibers: the first is to maximize
axial thermal conductivity through multiscale structural engineering, and the second is to go beyond pure