Red wine may be key to next-gen wearable techBy Eleanor Field
A team of scientists at the University of Manchester are using tannic acid from red wine, coffee or black tea to develop more flexible and durable wearable devices.
According to the research, the addition of tannins improved mechanical properties of materials such as cotton to develop wearable sensors for rehabilitation monitoring, significantly increasing the longevity of a device.
The team have developed wearable devices such as capacitive breath sensors and artificial hands for extreme conditions by improving the durability of flexible sensors.
Wearable technology has deteriorated in the past after repeated bending and folding due to the consequent micro cracks which can interrupt the conductivity a device.
Dr Xuqing Liu, who led the research team, said: “Traditional conductive material suffers from weak bonding to the fibers which can result in low conductivity. When red wine, or coffee, or black tea, is sprinkled on a dress, it will be difficult to get rid of these stains.
“The main reason is that they all contain tannic acid, which can firmly adsorb the material on the surface of the fiber. This good adhesion is exactly what we need for durable wearable, conductive devices.”
Published in the journal Small, the new research suggests that without the layer of tannic acid, the conductivity is several hundred times, potentially thousands of times, less than traditional conductive material samples as the conductive coating becomes easily detached from the textile surface due to repeated bending and flexing.
The improved conductivity using natural sources could allow technology developers to to replace materials such as nylon with more comfortable fabrics including cotton.
Enabling circuits to be printed directly on to the surface of clothing, the technology could also offer a more flexible circuit board.
The ultimate impact of this new process could see an improvement in both the comfort and robustness of wearable technology alongside a reduction in price.