Functional Graphene Fiber Materials for Advanced Wearable Applications

Nanoscience Electrical Engineering Mechanical Engineering Organic Polymeric Materials Chemistry Materials Science Engineering Materials Chemistry
graphene fibers wearable electronics flexibility energy storage devices smart textiles

Academic Background

With the rapid development of wearable electronic devices, the demand for high-performance, flexible, and durable materials has been increasing. Graphene, as a two-dimensional material with excellent electrical conductivity, mechanical strength, and flexibility, has garnered significant attention in recent years for its applications in wearable electronics. However, transforming graphene into functional fiber materials suitable for wearable devices remains a challenge. Graphene fiber (GF), as a novel fiber material, not only inherits the outstanding properties of graphene but also possesses the flexibility and weavability of textiles, making it highly promising for applications in wearable sensing, flexible energy storage devices, and smart textiles. This review summarizes the fabrication techniques of graphene fibers and their applications in wearable electronics, aiming to provide directions for future research and promote the commercialization of graphene fibers.

Source of the Paper

This review paper was co-authored by Heng Zhai, Jing Liu, Zekun Liu, and Yi Li, affiliated with the Department of Materials at the University of Manchester and the Botnar Research Center at the University of Oxford. The paper was accepted on January 5, 2025, and published in the journal Advanced Fiber Materials in the same year, with the DOI 10.1007/s42765-025-00512-1.

Main Content of the Paper

1. Fabrication Techniques of Graphene Fibers

The fabrication of graphene fibers is a crucial step in their application to wearable devices. The paper details three main preparation methods: wet spinning, electrospinning, and dry spinning.

  • Wet Spinning: This is the most common method, involving the spinning of graphene oxide (GO) liquid crystal solutions into a coagulation bath to form continuous fibers. Wet spinning can produce graphene fibers with excellent mechanical properties and conductivity. The paper also mentions that the quality of the GO dispersion, the choice of spinning nozzle, and the composition of the coagulation bath need to be controlled to ensure fiber performance.

  • Electrospinning: This method uses a high-voltage electric field to spin GO dispersions into nanofibers, producing graphene nanofibers (GNF) with high conductivity and tensile strength. The advantage of electrospinning lies in its ability to produce continuous fibers with diameters ranging from 100 to 900 nanometers, suitable for large-scale production.

  • Dry Spinning: Dry spinning directly extrudes GO solutions into fibers without a coagulation bath. Although the fibers produced by this method are lightweight, their mechanical strength is lower due to the absence of a solvent exchange process.

2. Structure and Properties of Graphene Fibers

The structural design of graphene fibers significantly impacts their performance. The paper introduces various structural designs, such as twisted structures, hollow structures, and ribbon structures, which can significantly enhance the mechanical properties and conductivity of the fibers.

  • Twisted Structure: By twisting two wet GO fibers together, parallel-aligned graphene sheets are formed, improving the tensile strength and breaking strain of the fibers.

  • Hollow Structure: Hollow graphene fibers have a high specific surface area and conductivity, making them suitable for flexible supercapacitors and batteries.

  • Ribbon Structure: Ribbon-shaped graphene fibers produced by wet spinning exhibit high flexibility and strength, enabling the formation of complex microstructures suitable for elastic strain sensors and flexible solar cells.

3. Applications of Graphene Fibers in Wearable Electronics

The applications of graphene fibers in wearable electronics mainly include sensing technologies, flexible energy storage devices, and flexible displays and circuits.

  • Sensing Technologies: Graphene fibers can function as strain, pressure, and humidity sensors, enabling real-time monitoring of environmental and mechanical changes. For example, graphene fibers coated with functional materials can detect humidity, pressure, or strain, making them ideal for health monitoring and human-machine interfaces.

  • Flexible Energy Storage Devices: Graphene fibers demonstrate excellent performance in supercapacitors and batteries, maintaining efficient energy storage under bending and stretching conditions. The paper also highlights the conductivity and mechanical strength of graphene fibers, making them ideal materials for flexible energy storage devices.

  • Flexible Displays and Circuits: The high conductivity and flexibility of graphene fibers allow them to be woven into light-emitting devices or serve as the basis for wearable circuits. For instance, multistrand twisted graphene fibers can significantly enhance display brightness and circuit stability.

4. Future Directions for Graphene Fibers

The paper points out that future research will focus on improving the structural performance of graphene fibers, hybridizing them with other materials, and developing scalable fabrication techniques. By optimizing the quality and alignment of graphene sheets, the mechanical properties and conductivity of fibers can be further enhanced. Additionally, the large-scale production of graphene fibers will promote their widespread application in smart textiles and wearable devices.

Significance and Value of the Paper

This review paper comprehensively summarizes the fabrication techniques of graphene fibers and their applications in wearable electronics, providing important references for future research. By discussing the structural design, performance optimization, and application prospects of graphene fibers in detail, the paper not only advances the innovative applications of graphene fibers in wearable devices but also paves the way for the commercialization of smart textiles. Furthermore, the paper emphasizes the enormous potential of graphene fibers in flexible energy storage, sensing, and display fields, offering new insights for the development of next-generation wearable electronics.

Highlights and Innovations

  • Multistructural Design: The paper details various structural designs of graphene fibers, such as twisted, hollow, and ribbon structures, demonstrating significant improvements in mechanical properties and conductivity.

  • Multifunctional Applications: The wide range of applications of graphene fibers in sensing, energy storage, and displays highlights their immense potential in wearable electronics.

  • Scalable Fabrication Techniques: The paper explores scalable fabrication techniques such as wet spinning, electrospinning, and dry spinning, providing a technical foundation for the commercialization of graphene fibers.

Conclusion

Graphene fibers, as a novel functional material, exhibit vast application prospects in wearable electronics. By optimizing fabrication techniques and structural designs, graphene fibers can not only enhance the performance of wearable devices but also promote the large-scale application of smart textiles. Future research will continue to explore the potential of graphene fibers, driving their widespread use in the field of flexible electronics.