Imagine if you could recharge your smartphone while walking around European researchers have invented a T-shirt that captures the body's energy and converts it into electricity.
So will it be possible in the near future to make the same T-shirt reflective or to recharge a smartphone placed in its pocket?
How to turn a T-shirt into a mini power plant Physics has shown us that there are two ways of doing so: piezoelectricity, which uses motion to generate energy in clothing, or the thermoelectric effect, which converts temperature differences into electrical voltage.
A team of researchers from the University of Malaga and the Italian Institute of Technology have chosen the latter method, presenting a connected garment that works thanks to the difference between the temperature of the body and that of the environment.
What is the guiding principle? If two conductors are connected and one side is heated, the electrons move to the cooler side, creating a current that flows through the circuit.
Up to now , the materials used as conductors to convert this temperature difference into a power source, for example in the automobile industry, have been metals. They are not only toxic and environmentally unfriendly, but are also scarce and expensive. Tellurium, for example, is about the same price as gold.
An e-textile made out of tomato skin!
To integrate electronics into textiles, it was necessary to push innovation to the extreme of somehow identifying an electronic device that would be biodegradable.
José Alejandro Heredia explains that he came up with his concept of connected clothing by incorporating tomato skin into the cloth! This cheap material is a waste product of the tomato processing industry, to which the researchers propose to give a new life.
As a result of having ethanol and carbon nanoparticles added to it, the tomato skin incorporated into the cotton of the garment acquires electrical properties when heated. The difference between the body temperature and the ambient temperature thus produces the thermal energy needed to light up an LED on contact with the fabric.
So will it be possible in the near future to make the same T-shirt reflective or to recharge a smartphone placed in its pocket? Researchers must first find a way to store this electricity. Once this barrier is removed, the devices that can be incorporated into clothing offer a multitude of uses, limited only by the imagination.
The researchers explain that they have already developed a portable Wi-Fi antenna and mention other possibilities. In the field of biomedicine, for example, it is easy to imagine hearing aids or sensors monitoring the user's signals. Thermoelectric textiles could also be used as instant body coolers when incorporated into sportswear. And in twenty years’ time, will there be a suit that allows us to fly like Iron Man?
CREDITS: Main picture ⓒ Noémie Rosset / Veolia