Graphene ink may enable 'smart' clothes

Scientists have developed conductive cotton fabrics using graphene-based inks that could lead to smart textiles and interactive clothes with applications ranging from healthcare to the Internet of Things.
Wearable textiles-based electronics present new possibilities for flexible circuits, healthcare and environment monitoring, energy conversion and many others.
Cotton fabric is among the most widespread for use in clothing and textiles, as it is breathable and comfortable to wear, as well as being durable to washing. These properties also make it an excellent choice for textile electronics.
Researchers at the University of Cambridge in the UK and Jiangnan University in China, have devised low-cost, sustainable and environmentally-friendly method for making conductive cotton textiles by impregnating them with a graphene-based ink.

The work demonstrates a wearable motion sensor based on the conductive cotton.
The team created inks of chemically modified graphene flakes that are more adhesive to cotton fibres than unmodified graphene. Heat treatment after depositing the ink on the fabric improves the conductivity of the modified graphene.

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.

These offer limited compatibility with the skin in many circumstances, are damaged when washed and are uncomfortable to wear because they are not breathable.
"Other conductive inks are made from precious metals such as silver, which makes them very expensive to produce and not sustainable, whereas graphene is environment-friendly, cheap and chemically compatible with cotton," said Torrisi.
"This method will allow us to put electronic systems directly into clothes. It's an incredible enabling technology for smart textiles," said Chaoxia Wang of Jiangnan University.
"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," said Torrisi.

"Thanks to nanotechnology, in the future our clothes could incorporate these textile-based electronics and become interactive," he added.
Graphene is changing the science and technology landscape with attractive physical properties for electronics.
Graphene's atomic thickness and excellent electrical and mechanical properties give excellent advantages, allowing deposition of extremely thin, flexible and conductive films on surfaces and - with this new method - also on textiles.
This combined with the environmental compatibility of graphene and its strong adhesion to cotton make the graphene-cotton strain sensor ideal for wearable applications.
The study was published in the journal Carbon.