The researchers created inks of chemically modified graphene flakes that are more adhesive to cotton fibres than unmodified grapx
The adhesion of the modified graphene to the cotton fibre is similar to the way cotton holds coloured dyes, and allows the fabric to remain conductive after several washes.
Although numerous researchers around the world have developed wearable sensors, most of the current wearable technologies rely on rigid electronic components mounted on flexible materials such as plastic films or textiles.
“Other conductive inks are made from precious metals such as silver, which makes them very expensive to produce and not sustainable, whereas graphene is both cheap, environmentally-friendly, and chemically compatible with cotton,” says Dr Felice Torrisi of the Cambridge Graphene Centre, “turning cotton fibres into functional electronic components can open to an entirely new set of applications from healthcare and wellbeing to the Internet of Things. Thanks to nanotechnology, in the future our clothes could incorporate these textile-based electronics and become interactive.”
The group’s work is based on the dispersion of graphene sheets in a water-based dispersion. The individual graphene sheets in suspension are chemically modified to adhere well to the cotton fibres during printing and deposition on the fabric, leading to a thin and uniform conducting network of many graphene sheets.
This network of nanometre flakes is the secret to the high sensitivity to strain induced by motion. A simple graphene-coated smart cotton textile used as a wearable strain sensor has been shown to reliably detect up to 500 motion cycles, even after more than 10 washing cycles in normal washing machine.
The use of graphene and other related 2D materials (GRMs) inks to create electronic components and devices integrated into fabrics and innovative textiles is at the centre of new technical advances in the smart textiles industry.