Mechanical Bonds Enable Stretchability–Strength Balance in Graphene-Based Fibers

BackgroundAdvancements in sports materials have led to the creation of innovative fabrics aimed at enhancing athletic performance and reducing the risk of sports-related injuries. Graphene-based composite fibers, with superior far-infrared (FIR) emissivity, are emerging as a promising material in sportswear. This study explores the effects of graphene-based FIR compression garments on aerobic exercise capacity.ResultsA total of 15 healthy, recreationally active male university students (aged 18–25 years) participated in this double-blind, randomized crossover trial. Each participant completed two incremental treadmill tests while wearing either graphene-based FIR compression garments or control garments, with a 7-day washout period between sessions. Results showed significantly longer exercise durations (38.4 s, p < 0.001) and extended time to anaerobic threshold (37.7 s, p < 0.001) in those wearing graphene-based FIR garments compared to those wearing control garments. The maximum heart rate was significantly lower in the graphene group (198.8 ± 7.8 bpm vs. 200.3 ± 7.5 bpm, p < 0.05), with reduced heart rates at the same exercise intensity (176.9 ± 8 bpm vs. 179.8 ± 7.8 bpm, p < 0.05). No significant differences in Maximal Oxygen Uptake (VO2max) were observed between the two groups.ConclusionsGraphene-based FIR compression garments significantly enhance aerobic performance by improving endurance, likely due to improved peripheral blood circulation and reduced cardiac load. These findings highlight the potential of graphene-based fibers as a disruptive innovation in sportswear. Further research with larger sample sizes is warranted to fully explore their benefits.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40798-025-00913-x.

Graphene-based materials have garnered interest as efficient sensing materials for gas sensors, demonstrating significant potential in medical applications for detecting biomarkers and serving as advanced tools for health monitoring and disease diagnosis. The distinct two-dimensional morphology of graphene, with its high surface area and continuous conductive network, is known to enhance the sensitivity of gas sensors by providing abundant active sites for gas adsorption and facilitating rapid electron transfer. Graphene fibers, formed by assemblies of graphene sheets into fibrous structures, have emerged as promising materials for gas sensor fabrication due to their exceptional electrical, chemical, and mechanical properties. Advantages of graphene fibers include their stability and tunability, allowing them to detect a broad spectrum of gases and making them highly versatile as sensing materials in gas-sensing applications. These graphene fibers leverage the exceptional sensitivity and selectivity of graphene with mechanical flexibility of fiber materials, enabling integration into wearable electronics and miniaturization of sensing devices.This work investigates graphene fibers for gas sensing applications and focuses on the preparation of these graphene-based composite fibers through fiber spinning techniques. The incorporation of graphene into polymeric or hybrid matrices provides sensing materials with enhanced gas adsorption and sensing performance that can be easily processable. Electrospinning enables the formation of ultrafine, uniform fibers, while wet-spinning offers control over fiber alignment and supports scalable production, enhancing the functional properties of the composite material. By tailoring the graphene dispersion, fiber morphology, and material composition, the resulting fiber sensors achieve improved stability, sensitivity, and selectivity. This study further presents the characterization of graphene-based composite fibers, emphasizing their electronic properties and structural morphology, which are critical to their performance in gas-sensing applications. This presentation also highlights the real-world practicality of graphene-based fiber sensors as advanced gas-sensing technologies, showcasing their ability to detect diverse biomarker gases and their potential in healthcare management for real-time monitoring.

The importance of gas sensors is apparent as the detection of gases and pollutants is crucial for environmental monitoring and human safety. Gas sensing devices also hold the potential for medical applications as health monitoring and disease diagnostic tools. Gas sensors fabricated from graphene-based fibers present a promising advancement in the field of sensing technology due to their enhanced sensitivity and selectivity. The diverse chemical and mechanical properties of graphene-based fibers-such as high surface area, flexibility, and structural stability-establish them as ideal gas-sensing materials. Most significantly, graphene fibers can be readily tuned to detect a wide range of gases, making them highly versatile in gas-sensing technologies. This review focuses on graphene-based composite fibers for gas sensors, with an emphasis on the preparation processes used to achieve these fibers and the gas sensing mechanisms involved in their sensors. Graphene fiber gas sensors are presented based on the chemical composition of their target gases, with detailed discussions on their sensitivity and performance. This review reveals that graphene-based fibers can be prepared through various methods and can be effectively integrated into gas-sensing devices for a diverse range of applications. By presenting an overview of developments in this field over the past decade, this review highlights the potential of graphene-based fiber sensors and their prospective integration into future technologies.

The recent flourishing development of two-dimensional (2D) graphene has sparked considerable interest and extensive research on graphene-based optical fiber polarizers. However, studies on graphene-optical fiber polarizers focused on the structure with graphene films attached to side-polished fibers, which face challenges such as low birefringence of 10-6, low polarization extinction ratio (PER), and narrow polarizing window of tens of nanometers. Here, a fiber polarizer based on a graphene-photonic crystal fiber (Gr-PCF) is proposed firstly, which exhibits high birefringence of ∼2.5 × 10-3, high PER of ∼111 dB/mm, broad polarizing window of >400 nm, and tunable polarization states. Graphene or graphene/hBN/graphene (Gr/hBN/Gr) heterojunctions are attached to the surface of two square holes in the PCF to make one of the polarizing modes attenuate significantly. The tunability of the Fermi level (EF) in Gr/hBN/Gr enables the proposed device to function as a polarizer or a polarization-maintaining fiber. The combination of PCF's endless single-mode feature and graphene's broadband optical response feature enables the fiber polarizer to exhibit a wide spectrum range with single-mode transmission characteristics.

Assembling graphene sheets into macroscopic fibers with graphitic layers uniaxially aligned along the fiber axis is of both fundamental and technological importance. However, the optimal performance of graphene-based fibers has been far lower than what is expected based on the properties of individual graphene. Here we show that both mechanical properties and electrical conductivity of graphene-based fibers can be significantly improved if bridges are created between graphene edges through covalent conjugating aromatic amide bonds. The improved electrical conductivity is likely due to extended electron conjugation over the aromatic amide bridged graphene sheets. The larger sheets also result in improved π-π stacking, which, along with the robust aromatic amide linkage, provides high mechanical strength. In our experiments, graphene edges were bridged using the established wet-spinning technique in the presence of an aromatic amine linker, which selectively reacts to carboxyl groups at the graphene edge sites. This technique is already industrial and can be easily upscaled. Our methodology thus paves the way to the fabrication of high-performance macroscopic graphene fibers under optimal techno-economic and ecological conditions.

Wet-spinning of reduced graphene oxide composite fiber by mechanical synergistic effect with graphene scrolling method

3D Architecting triple gradient graphene-based fiber electrode for high-performance asymmetric supercapacitors

After the first report of a graphene-based passive mode-locking ultrafast fiber laser, two-dimensional materials as efficient saturable absorbers offer a new horizon in ultrafast fiber laser. However, the interactions on atomic scale between these two-dimensional materials and fiber and the fiber effect on the carrier dynamics have not been realized. To figure out the exact role of fiber and the carrier dynamics affected by the fiber substrate related to ultrafast photonics, bismuthene, a newly reported 2D quantum material used in a passive mode-locking fiber laser, deposited on α-quartz has been investigated. We surprisingly found that the α-quartz substrate can strongly accelerate the nonradiative electron-hole recombination of bismuthene in theory, and the transient absorption spectra of bismuthene on normal glass and α-quartz further verify the substrate effect on carrier dynamics of bismuthene. The discovery provides new thinking about substrate effect to regulate the performance of ultrafast mode-locking fiber lasers as well as ultrafast photonics.

Biological materials exhibit fascinating mechanical properties for intricate interactions at multiple interfaces to combine superb toughness with wondrous strength and stiffness. Recently, strong interlayer entanglement has emerged to replicate the powerful dissipation of natural proteins and alleviate the conflict between strength and toughness. However, designing intricate interactions in a strong entanglement network needs to be further explored. Here, we modulate interlayer entanglement by introducing multiple interactions, including hydrogen and ionic bonding, and achieve ultrahigh mechanical performance of graphene-based nacre fibers. Two essential modulating trends are directed. One is modulating dynamic hydrogen bonding to improve the strength and toughness up to 1.58 GPa and 52 MJ/m3, simultaneously. The other is tailoring ionic coordinating bonding to raise the strength and stiffness, reaching 2.3 and 253 GPa. Modulating various interactions within robust entanglement provides an effective approach to extend performance limits of bioinspired nacre and optimize multiscale interfaces in diverse composites.

Flexible microwave absorbing fabrics woven by high-strength graphene-based hybrid fibers with broadband electromagnetic response

Anchoring polypyrrole on nitrogen and sulfur codoped graphene fibers to construct flexible supercapacitors

A passive mode-locked erbium-doped fiber laser based on graphene operating in the anomalous dispersion state is designed in this paper. In this experiment, the complete convert process from traditional soliton pulses to soliton rains and bound-state (BS) soliton pulses, and ultimately to traditional soliton pulses, is achieved by adjusting the pump power and polarization controller (PC) to control factors such as nonlinearity, dispersion, and birefringence in the cavity. In the BS soliton state, switching between the 0 phase and π phase BS solitons is achieved. We also replaced the 20/80 coupler with the 30/70 coupler to achieve the soliton rains by varying the energy alteration of the intracavity pulse. When the pump power is increased to 350 mW, the laser generates multi-pulses and eventually forms a new BS. In addition, we also studied the soliton vector characteristics during this conversion process and found the polarization-locked vector soliton (PLVS). The research results enrich nonlinear vector soliton dynamics and provide valuable data for further theoretical studies.

Hypothesis-driven methods to tailor the functionality, topology, carbon orientation, and three-dimensional (3D) structure of carbon microelectrodes, for specific classes of neurochemicals, would significantly improve analyte specificity and lower the limits of detection for fast-scan cyclic voltammetry (FSCV) detection in the brain and beyond. FSCV at carbon-fiber microelectrodes is an established technique to study the signaling dynamics of many different neurochemicals in the brain. Despite its widespread applicability to many analytes, most in vivo studies are conducted on bare, unmodified carbon-fiber microelectrodes and many of the fundamental studies of new electrode materials focus on dopamine detection. Manipulations of the carbon surface can have profound effects on electrochemical detection and carefully controlled experiments to manipulate the analyte-electrode interface could provide exquisite information for future design of electrode materials. Here, we will discuss our latest work on synthesizing and manipulating the surfaces of carbon-based materials including graphene-based fibers and porous PAN-derived carbon-fiber, to exploit specific neurochemical-electrode interactions for improved detection. This presentation will demonstrate the importance of understanding the analyte-structure-electrode-surface interface for designing optimal electrodes.

A novel graphene-based circular dual-core photonic crystal fiber pressure sensor with high sensitivity

Microfluidic-oriented assembly of Mn3O4@C/GFF cathode with multiscale synergistic structure for high-performance aqueous zinc-ion batteries

Effects of nano-particles on the MRR and TWR of graphene-based composite by EDM using copper tool

ConspectusTwo-dimensional (2D) materials with astonishing properties and thickness dimensions are attractive for nanodevices and optoelectronics devices. Among them, 2D graphene─an atomically thin single layer with a strong covalently bonded sp2-hybridized hexagonal carbon network─has fascinating physicochemical properties. 2D graphene is at the tip of the iceberg of 2D materials. However, graphene is prone to self-restacking and agglomeration, deteriorating its properties. The introduction of porous structures to graphene sheets ameliorates their properties, e.g., increasing the surface area, providing ion transport channels, and enhancing the stability; thus, the performance of graphene-based materials is improved. Owing to their exciting properties, 2D holey graphene (HG) with nanoholes in its 2D basal plane and three-dimensional (3D) porous graphene with structural pores and interconnected architectures structural derivatives of graphene are promising for addressing the aforementioned challenges synergistically. Perforation in 2D graphene with tunable pore size, pore density, and uniformity is crucial for improving the performance of dense graphene. The unique pore structure and large exposed edges indicate the improved properties of porous graphene. Furthermore, macroscopically assembled one-dimensional (1D) fibrous electrodes of holey and porous graphene building blocks are promising, as they are lightweight, have high flexibility, and have strong wearability for future next-generation electronics.In this Account, we systematically highlight our efforts related to the conventional synthesis methodologies to recent emerging methods of “holey” or “porous” graphene/graphene oxide. First, we focus on the synthesis strategies and advances of 2D HG in-plane holes suitable for fast ion transport. Recent emerging synthesis methodologies are discussed for preparing 2D HG, which uses an environmentally benign approach with low toxicity compared to conventional etching methods, which frequently involve the use of hazardous or toxic oxidizing reagents, thereby causing severe environmental pollution. Second, compared with graphene, the 3D porous graphene comprises self-assembled graphene sheets (holey) containing structural macropores with a larger accessible surface area, high pore volume, and better flexibility, stability, and mechanical properties preferred for energy conversion and storage applications. Here, the recent progress and emerging synthesis approaches for 3D porous graphene-based nanomaterials are comprehensively discussed. Furthermore, the advantages of 2D HG and 3D porous graphene are discussed for water transport and electrochemical storage. Third, recent advances in the use of straightforward, large-scale wet-spinning processes to fabricate macroscopically assembled 1D fibrous electrodes with excellent mechanical flexibility and deformability using holey or porous graphene-based fibers (GFs) are described. Different approaches are discussed for preparing holey or porous GFs, such as wet-spinning assembly of holey graphene oxide (HGO), coagulant-assisted porous structures, and the post-activation process. Thus, the wet-spun holey or porous GFs are promising for miniaturized-based next-generation wearable electronic devices. Finally, we focus on the current status, fundamental understanding, future directions, and challenges of wet-spinning assemblies of holey/porous graphene-based nanomaterials for the next generation of wearable electronics.

Abstract Polyacrylonitrile (PAN) fiber is soft and comfortable, but its poor strength compared to other synthetic fibers has limited it wide range of applications. This study effectively improved the strength of PAN fibers by adding graphene oxide (GO) and polyvinyl alcohol (PVA) during PAN spinning. The composite fibers were prepared via gel spinning and subsequent hot drawing process. The results show that the PVA molecular chains embedded into the PAN molecular chain significantly improved the mechanical properties of the hybrid fiber. At the same time, the defect reduced the UV resistance and thermal stability of the hybrid fibers only when the PVA molecular was introduced in the PAN. Surprisingly, after the recomposition of GO in the above mixed polymer system, the interaction between the GO and matrix not only improved the mechanical properties of the fiber, but also enhanced the UV resistance and thermal stability. In addition, when the amount of GO was 0.3 wt%, the crystallinity of the GO/PVA/PAN composite fiber reached the maximum and the tensile strength was the highest. This strategic approach suggests an effective method to prepare graphene-based ternary composites fibers with high strength and novel functional characteristics.

As one of the most promising energy storage devices, graphene-based fibrous supercapacitors (FSSCs) are attracting intensive attention. However, the conflict between specific capacitance and intrinsic brittleness of pure graphene fibers hinders their practical applications. Herein, we develop a strategy to fabricate graphene-based ternary composite CNT/MXene/graphene (CMG) fiber electrodes with high toughness and high electrical and electrochemical performance. These resulting properties are attributed to the three-dimensional cross-linked conducting network within graphene sheets through covalent bonding and π–π interaction among acidified carbon nanotubes, graphene sheets, and MXene, which greatly contributes to the enhanced tensile strength, toughness, and electrical transport in the CMG fiber. The CMG fiber with the optimized mass ratio of different components shows a high toughness of ∼1.7 MJ m–3 and an electrical conductivity of 420 S cm–1, which is 4- and 2-fold that of reduced graphene oxide fiber, respectively. The assembled FSSC based on the optimized CMG fiber exhibits an areal capacitance of 237 mF cm–2 and a good rate performance of 85%.