Researchers have developed a single strand of fibre that has the flexibility of cotton and the electric conductivity of a polymer, called polyaniline.
- The newly developed material showed good potential for wearable e-textiles.
- Washington State University (WSU) researchers tested the fibres with a system that powered an LED light and another that sensed ammonia gas.
- The fibre has two sections. One section is the conventional cotton: flexible and strong enough for everyday use, and the other side is the conductive material.
- The cotton can support the conductive material which can provide the needed function.
The research: The findings have been detailed in the journal Carbohydrate Polymers. Hang Liu, WSU textile researcher, was the study’s corresponding author. Additional WSU authors on this study included first author Wangcheng Liu as well as Zihui Zhao, Dan Liang, Wei-Hong Zhong and Jinwen Zhang.
- This research received support from the National Science Foundation and the Walmart Foundation Project.
The details: The idea behind the project was to integrate fibres like these into apparel as sensor patches with flexible circuits.
- These patches could be part of uniforms for firefighters, soldiers or workers who handle chemicals to detect for hazardous exposures. Other applications include health monitoring or exercise shirts that can do more than current fitness monitors.
- The WSU team worked to overcome the challenges of mixing the conductive polymer with cotton cellulose. Polymers are substances with very large molecules that have repeating patterns. In this case, the researchers used polyaniline, also known as PANI, a synthetic polymer with conductive properties already used in applications such as printed circuit board manufacturing.
- While intrinsically conductive, polyaniline is brittle and by itself, cannot be made into a fibre for textiles. To solve this, the WSU researchers dissolved cotton cellulose from recycled t-shirts into a solution and the conductive polymer into another separate solution.
- These two solutions were then merged together side-by-side, and the material was extruded to make one fibre.
- The result showed good interfacial bonding, meaning the molecules from the different materials would stay together through stretching and bending.
- Achieving the right mixture at the interface of cotton cellulose and polyaniline was a delicate balance. The scientists wanted these two solutions to work so that when the cotton and the conductive polymer contact each other they mix to a certain degree to kind of glue together, but we didn’t want them to mix too much, otherwise the conductivity would be reduced.
What they said:
We have some smart wearables, like smart watches, that can track your movement and human vital signs, but we hope that in the future your everyday clothing can do these functions as well. Fashion is not just colour and style, as a lot of people think about it: fashion is science.
— Hang Liu (Corresponding author)
Textile Researcher
Washington State University
