Energy storage incorporated directly into fabric

Using graphene inks, a team at Cambridge University claims clothing could be turned into washable, wearable electricity source

New types of wearable electronic devices could be developed from capacitors and other charge storage components formed from fabric into which graphene and related materials are directly incorporated, according to researchers from the Cambridge Graphene Centre, collaborating with colleagues at Jiangnan University in China. The technology relies on standard techniques for dying polyester fabric with inks made by solution processing techniques.

Schematic of the textile-based capacitor integrating graphene/polyesters as electrodes and hexagonal boron nitride/polyesters as dielectrics. Credit: Felice Torrisi

In a paper in the journal Nanoscale, Felice Torrisi of the Graphene Centre and colleagues explain that while other techniques to incorporate electronic components into textiles depend on components mounted on plastics that cannot be washed and are uncomfortable to wear, the new technique creates electric circuits by “simply overlaying different fabrics made of two-dimensional materials” onto polyester.

The researchers suspended graphene sheets in a low boiling point solvent to make the ink, which can be dyed onto polyester. Overlaying this fabric with fabric similarly dyed with hexagonal boron nitride, another two-dimensional conductive material, creates an active region that works as a capacitor, enabling charge storage. The fabric remains bendable, breathable, and can withstand cycles in a normal washing machine.

“Textile dyeing has been around for centuries using simple pigments, but our result demonstrates for the first time that inks based on graphene and related materials can be used to produce textiles that could store and release energy,” said Prof Chaoxia Wang from Jiangnan. “Our process is scalable and there are no fundamental obstacles to the technological development of wearable electronic devices both in terms of their complexity and performance.”

While not the same as batteries in technological terms, capacitors can be used similarly to power electronic devices, although these have to be specifically designed for this type of power source. The Cambridge team suggests that personal health and well-being devices, data storage, military garments, wearable computing and fashion elements such as lighting are particularly suitable candidates for devices that could be powered using this type of technology.

“Turning textiles into functional energy storage elements can open up an entirely new set of applications, from body-energy harvesting and storage to the Internet of Things,” said Torrisi “In the future our clothes could incorporate these textile-based charge storage elements and power wearable textile devices.”