New Material: Researchers Have Developed A New Type Of Cotton Fiber That Can Conduct Electricity

Researchers have developed a new type of fiber, which has both the flexibility of cotton and the conductivity of polyaniline polymer. This innovative material is available in Carbohydrate Polymers), which shows the potential of manufacturing wearable electronic textiles, and can be used for health monitoring, hazard exposure detection and other applications.

A single strand fiber developed by Washington State University has both the flexibility of cotton and the conductivity of a polymer called polyaniline, showing great potential in wearable electronic textiles. Researchers at Washington State University used a LED lamp powered system and another ammonia sensing system tested this fiber, and their research results were detailed in the journal Carbohydrate Polymer.

The microscopic image of the newly developed fiber shows that the cotton is mixed side by side, and the polyaniline polymer that can carry electric current is contained on the other side. Source: Washington State University

Liu Hang, a textile researcher at Washington State University and the corresponding author of the study, said: "We divide a fiber into two parts: one is traditional cotton: flexible and strong enough to meet daily use, and the other is conductive material. Cotton can support conductive materials, and conductive materials can provide the required functions."

Potential applications of wearable technology

Although more development work is needed, the idea of researchers is to integrate such fibers into clothing as sensor patches with flexible circuits. These patches can be part of the uniforms of firefighters, soldiers or workers handling chemicals to detect exposure to hazardous substances. Other applications include health monitoring or sports shirts, which can do more than current fitness monitors.

Liu said: "We now have some intelligent wearable devices, such as smart watches that can track your movement and human vital signs, but we hope that in the future your daily clothes can also achieve these functions. Fashion is not just color and style as many people think, but science itself."

Liu Hang, a textile researcher at Washington State University. Source: Dean Hare, Washington State University

Technical challenges and solutions

In this study, the Washington State University team worked hard to overcome the problem of mixing conductive polymers with cotton cellulose. Polymer is a kind of macromolecular substance with repeated pattern. In this case, the researchers used polyaniline (also known as PANI), a synthetic polymer with conductive properties, has been used in applications such as printed circuit board manufacturing.

Although polyaniline itself is conductive, it is relatively brittle and cannot be made into textile fibers. In order to solve this problem, researchers from the University of Western Sydney will The cotton cellulose extracted from the T-shirt is dissolved in one solution, and the conductive polymer is dissolved in another separate solution. The two solutions are then combined side by side to extrude the material into a fiber.

Hang Liu, Textile Researcher, Washington State University Watch the microscopic image of the newly developed fiber. The image shows that the fiber is mixed side by side, with cotton on one side and polyaniline polymer that can carry electric current on the other side. Source: Dean Hare, Washington State University

The results show that the interface is well bonded, which means that the molecules of different materials can be kept together in the process of stretching and bending. It is a delicate balance to achieve proper mixing at the interface of cotton cellulose and polyaniline.

Liu said: "We hope that these two solutions can play a role, so that when cotton and conductive polymer contact each other, they will be mixed together to a certain extent to form a kind of adhesive, but we do not want them to mix too much, or the conductivity will be reduced."

Reference: New Structural Design of Cellulose based Conductive Composite Fibers for Wearable Electronic Textiles by Wangcheng Liu, Hang Liu and Zhihui Zhao, Dan Liang, Wei Hong Zhong and Jinwen Zhang, August 18, 2023, Carbohydrate Polymers.