Washable, wearable batteries could be woven into clothes

Wearable electronic components incorporated directly into fabrics have been developed by researchers at the University of Cambridge, and could be used for applications including flexible circuits, healthcare monitoring, energy conversion and more.

Working in collaboration with China’s Jiangnan University, the researchers showed how graphene — a two-dimensional form of carbon — and other related materials can be directly incorporated into fabrics to produce charge storage elements such as capacitors, paving the way to textile-based power supplies that are washable, flexible and comfortable to wear. Their research, published in the journal Nanoscale, demonstrates that graphene inks used in textiles are able to store electrical charge and release it when required.

Most wearable electronics rely on rigid electronic components mounted on plastic 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.

By contrast, the researchers designed inks that can be directly coated onto a polyester fabric in a simple dyeing process. The process is low cost, sustainable, scalable and versatile, allowing various types of electronic components to be incorporated into the fabric.

“Other techniques to incorporate electronic components directly into textiles are expensive to produce and usually require toxic solvents, which makes them unsuitable to be worn,” said Dr Felice Torrisi from the Cambridge Graphene Centre, the study’s corresponding author. “Our inks are cheap, safe and environmentally friendly, and can be combined to create electronic circuits by simply overlaying different fabrics made of two-dimensional materials on the fabric.”

The researchers suspended individual graphene sheets in a low-boiling-point solvent, which is easily removed after deposition on the fabric, resulting in a thin and uniform conducting network made up of multiple graphene sheets. The subsequent overlay of several graphene and hexagonal boron nitride (h-BN) fabrics creates an active region, which enables charge storage. This sort of ‘battery’ on fabric is bendable and can withstand washing 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 co-author Professor Chaoxia Wang from Jiangnan University. “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.”

The work opens a number of commercial opportunities for ink based on two-dimensional materials, ranging from personal health and wellbeing technology to wearable energy and data storage, military garments, wearable computing and fashion.

“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 Dr Torrisi. “In the future, our clothes could incorporate these textile-based charge storage elements and power wearable textile devices.”

Image caption: Schematic of the textile-based capacitor integrating GNP/polyesters as electrodes and h-BN/polyesters as dielectrics. Image credit: Felice Torrisi.

This article is a modified version of a news item published by the University of Cambridge under CC BY 4.0

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