The wire is
completely free from metal. It consists of silk dyed with an electrically
conductive plastic. The researchers have developed a "dye" for
textiles that both dyes fabrics and threads beautifully blue, while at the same
time making them electrically conductive. The electrically conductive component
is a kind of polymer or plastic which, when dissolved in water, has a low pH
which makes it firmly stick on silk. This makes the threads withstand both
abrasion and washing after staining.The textile
takes a step closer to smart clothes with built-in features, without metals or
other materials that affect the feeling of fabric. The thread could also be
used for embroidered circuit boards in fabric.
“With an
electrically conductive silk wire comes new possibilities for designing textile
electronics, which can be used for, for example, pulse and movement sensors, fully integrated
in clothing. One can also imagine sewing a keyboard that can easily be rolled
up and put in the pocket”, says Dr. Anja Lund, who is part of the Christian
Müller research group.
In order to
successfully weave the thread into a fabric, Chalmers went to the handicraft
association Göteborgs Hemslöjdsförening, because of their good looms and great
weaving experience.
“The handicraft
association has been crucial for this project, since we have had to combine new
materials with traditional crafts. We also have machine-embroidered
electrically conductive patterns out of the wire, with help from the company
ACG Nyström in Borås. It is a very nice thing to be able to use local knowledge
in our work, "says Anja Lund.
The
researchers now want to move on and combine the conductivity in the thread with
their previous research findings, where they developed textiles that generate
electricity from heat. Together, this could lead to smart clothes that use the
body heat to support the features with electricity.
Text and image: Mats Tiborn