(Nanowerk Spotlight) The integration of electronics into clothing promises to transform how we interact with technology, but the fundamental materials have consistently fallen short. Attempts to weave electronic functions into textiles typically produce either stiff, unwearable materials or delicate structures that fail under normal use. The core challenge stems from the conflicting requirements: electronic components need stable structures to function reliably, while clothing must flex and stretch freely with movement.
Materials scientists have explored various approaches to bridge this divide. Metal wires prove too rigid and prone to breaking. Conductive polymers lack sufficient electrical performance. Carbon-based materials show promise but typically require harsh chemical processing that compromises their durability. Even when researchers successfully create flexible electronic fibers, they often degrade rapidly with washing or repeated movement—making them impractical for real-world clothing.
Carbon nanotubes represent a particularly tantalizing solution. These microscopic cylinders of carbon atoms naturally conduct electricity and can flex without breaking. However, processing them into usable fibers has required either strong acids that weaken their structure or chemical additives that interfere with their electrical properties. The challenge has been finding a way to organize carbon nanotubes into strong, flexible fibers while preserving their valuable electronic characteristics.
Korean scientists have now developed a chemical process that overcomes these limitations. Their method modifies carbon nanotubes to mix readily with common solvents while using a more controlled oxidation process, minimizing structural damage. The research team carefully controlled the oxidation of these nanotubes at low temperatures, attaching oxygen-containing groups while maintaining their electrical properties. Adding precisely sized particles of graphene oxide, an ultra-thin form of carbon, creates a mixture that forms strong fibers when spun.
Less-defective and highly oxidized single-walled carbon nanotubes (SWCNTs). a, Scheme of hydrogen-bonded assembly of SWCNTs inspired by biomaterials such as cellulose fibers (left) and spider silk (right). b, Scheme of kinetically controlled oxidation of SWCNTs by kneading at low temperature. (Image: Reprinted with permission by American Chemical Society) (click on image to enlarge)
A key feature of this method is that the fibers form a hierarchical structure, similar to natural materials like spider silk. As the nanotube mixture is ejected from a multi-hole spinneret, the individual streams naturally merge into a single, interwoven fiber. This self-assembling process, driven by hydrogen bonding, ensures the fibers are strong yet flexible, mimicking the way spider silk strands combine to form a tough, lightweight thread.
Standard textile manufacturing equipment can process this mixture into threads. Multiple thin streams exit through a spinneret device and naturally merge into a single fiber. The components link through hydrogen bonds—the same type of molecular connection found in natural fibers—creating a structure that combines strength with flexibility.
Testing revealed exceptional performance metrics. The fibers detected nitrogen dioxide gas at concentrations of 8.5 parts per billion, surpassing existing sensor sensitivity thresholds. Their energy storage capacity reached 320 Farads per gram at an extremely high current density of 32 A/g, maintaining this level through rapid charging cycles and 20,000 charge-discharge sequences. The fibers retained 99% of their original efficiency even after these cycles, demonstrating remarkable long-term stability.
A prototype necklace made by braiding these fibers with normal threads powered an LED light continuously. The necklace retained its electronic function after machine washing, demonstrating durability previously unseen in electronic textiles.
The manufacturing method offers clear practical benefits. It uses standard organic solvents instead of highly corrosive superacids, making it more compatible with existing textile production facilities. The process creates fibers that match both the durability requirements of clothing and the electronic capabilities of solid-state devices.
This development bridges a crucial gap between electronics and textiles. These fibers combine the electrical storage capacity needed for practical electronic devices with the physical properties required for wearable items. The successful integration of high-performance electronic functions into washable, flexible fibers establishes a foundation for manufacturing practical electronic clothing at industrial scales.
Get our Nanotechnology Spotlight updates to your inbox!
Thank you!
You have successfully joined our subscriber list.
Become a Spotlight guest author! Join our large and growing group of guest contributors. Have you just published a scientific paper or have other exciting developments to share with the nanotechnology community? Here is how to publish on nanowerk.com.
