Clothes will be able to produce electricity, says scientific research.
A study group at the Chalmers University of Technology in Sweden has discovered a technology capable of covering a silk thread with a conductive plastic material, thus transforming the fabrics into energy sources.
Silk dresses that can charge your smartphone or monitor your heart rate simply by wearing them. The principle behind this innovation is that of thermoelectric fabrics, which convert temperature differences, for example between our body and the surrounding air, into an electrical potential. A very useful technology in daily life. Connected to a sensor, these fabrics can power devices without the need for batteries. Since fabrics must be worn close to the body, the materials used must be safe and flexible. Hence the idea of using silk thread, which is flexible, light and non-toxic.
The method used to create the “electric silk” thread is the same used in previous studies within the same research project. In early attempts, however, the wire contained metals to maintain its stability in contact with air. Today we have achieved the production of a thread made exclusively of carbon-based organic polymers. The new proposal also has greater electrical conductivity and stability.
We’ve found the missing piece of the puzzle to making optimal thread: a recently discovered type of polymer. It has exceptional performance stability in contact with air and, at the same time, excellent ability to conduct electricity. By using polymers, we don’t need rare earth metals, which are common in electronics
explains Mariavittoria Craighero, PhD student in Applied Chemistry and Chemical Engineering.
To demonstrate how the new thread can be used in practice, the researchers created two thermoelectric generators: a button sewn with thread and a piece of fabric with threads sewn on. When they placed the thermoelectric fabrics between a hot and cold surface, they could observe the increase in voltage on the measuring instrument. The effect depended on the temperature difference and the amount of conductive material present in the fabric. For example, the largest piece of fabric showed about 6 millivolts at a temperature difference of 30 degrees Celsius. In the future, this discovery could be used to charge portable electronic devices via a simple USB. Furthermore, fabrics made with this special thread are machine washable.
After seven washes, the polymer retained two-thirds of its conductive properties. This is a very good result, although it needs to be further improved before it becomes commercially interesting
added the doctoral student.
There are still many issues to be resolved to make the use of this thread replicable on a large scale. Currently, in fact, it must be sewn by hand, a process that requires a lot of time and effort. However, researchers remain optimistic about the potential of this technology and believe that it will be possible to develop an automated, industrial-scale process in the future.
