Researchers have come up with an ordinary silk thread coated with a conductive plastic material that shows promising properties for turning textiles into electricity generators.
- The silk thread that the researchers tested has a coating made of a conducting polymer. It is a plastic material with a chemical structure that makes the material electrically conductive and well adapted to textiles.
- The researchers, led by scientists from Chalmers University of Technology in Sweden, have been able to show that the thread’s performance is maintained for at least a year. It is also machine washable.
THE MATERIAL: The polymers used are bendable, lightweight and are easy to use in both liquid and solid form. They are also non-toxic.
- To show how the new thread can be used in practice, the researchers manufactured two thermoelectric generators—a button sewn with the thread, and a piece of textile with sewn-in threads.
- When they placed the thermoelectric textiles between a hot and a cold surface, they could observe how the voltage increased on the measuring instrument. The effect depended on the temperature difference and the amount of conductive material in the textile.
- As an example, the larger piece of fabric showed about 6 millivolts at a temperature difference of 30 degrees Celsius. In combination with a voltage converter, it could theoretically be used to charge portable electronics via a USB connector.
- After seven washes, the thread retained two-thirds of its conducting properties. This is a very good result, although it needs to be improved significantly before it becomes commercially interesting.
THE CONTEXT: Interest in organic electronics with conjugated polymers has grown a lot in recent years.
- Research on conducting polymers is ongoing in many areas such as solar cells, the Internet of Things (IoT), augmented reality (AR), robotics and various types of portable electronics.
- Thermoelectric textiles convert temperature differences, for example between our bodies and the surrounding air, into an electrical potential. This technology can be of great benefit in our everyday lives and in society.
- Connected to a sensor, the textiles can power these devices without the need for batteries. These sensors can be used to monitor our movements or measure our heartbeat.
- Since the textiles must be worn close to the body, the materials used in them must meet high demands on safety and flexibility.
THE STUDY: The scientific articlePoly(benzodifurandione) Coated Silk Yarn for Thermoelectric Textiles is published in Advanced Science.
- Authors: Mariavittoria Craighero, Qifan Li, Zijin Zeng, Chunghyeon Choi, Youngseok Kim, Hyungsub Yoon, Tiefeng Liu, Przemysław Sowiński, Shuichi Haraguchi, Byungil Hwang,Besira Mihiretia,Simone Fabiano andChristian Müller.
- The researchers are active at Chalmers University of Technology, Linköping University and Chung-Ang University in Seoul, South Korea.
- The research has been funded by the EU's Horizon 2020 research and innovation programme, through the Marie Skłodowska-Curie project HORATES, the Knut and Alice Wallenberg Foundation, the European Research Council (ERC), the Swedish Research Council and Linköping University.
WHAT THEY SAID
We have now shown that it is possible to produce conductive organic materials that can meet the functions and properties that these textiles require. This is an important step forward. There are fantastic opportunities in thermoelectric textiles and this research can be of great benefit to society.
— Prof Christian Müller (Research Leader)
Department of Chemistry and Chemical Engineering
Chalmers University of Technology
