Scientists from the University of Manchester in the U.K. are hoping to improve wearable technology using acids from red wine, black tea and black coffee.

The team of scientists discovered that adding tannic acid extracted from red wine, black tea and black coffee to materials like cotton used to create wearable sensors improved the durability and flexibility of wearable devices. Added to the cotton, the tannic acid improved the mechanical properties of the material, thereby increasing the devices' lifespan.

While developing wearable devices like capacitive breath sensors and artificial hands, the team found that wearables often fail following repetitive bending and folding, which creates micro-cracks that interrupt the conductivity of the devices. By adding a layer of tannic acid to the material, researchers discovered that conductivity in the wearables improved by several hundred (even thousands) of times over conventional conductive materials because conductive coating easily detaches from textiles by way of repetitive flexing and bending.

Dr. Xuqing Liu who led the research team said: "We are using this method to develop new flexible, breathable, wearable devices. The main research objective of our group is to develop comfortable wearable devices for flexible human-machine interface.

"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."

Such a development could potentially enable developers of wearable technology to opt for more comfortable fabrics such as cotton instead of commonly used nylon, which tends to be stiff and uncomfortable. Likewise, the discovery could also enable circuits to print directly on the surface of clothing to create a flexible and comfortable circuit board.

The research appears in the journal Small.