Researchers have successfully incorporated washable, stretchable and breathable electronic circuits into the fabric. This opens up new possibilities for smart textiles and wearable electronics. The circuits were made with cheap, safe and environmentally friendly inks. They are printed using conventional inkjet printing techniques.
The research team from the University of Cambridge worked with colleagues in Italy and China to demonstrate how graphene can be directly printed onto fabric to produce integrated electronic circuits and be comfortable enough to wear and survive up to 20 cycles in a washing machine.
The new textile electronic devices are based on low-cost, sustainable and scalable inkjet printing of inks based on graphene and other 2D materials, and are produced by standard processing techniques.
Based on earlier work on the formulation of graphene inks for printed electronics, the team designed low-boiling point inks, which are directly printed onto polyester fabric. They also found that modifying the roughness of the fabric improved the performance of the printed devices. The versatility of the process allowed the researchers to design the single transistors and all-printed integrated electronic circuits combining active and passive components.
The most wearable electronic device currently available relies on rigid electronic components mounted on plastic, rubber 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 inks for printed electronics normally require toxic solvents and are not suitable to be worn, whereas our inks are both cheap, safe and environmentally friendly, and can be combined to create electronic circuits by simply printing different two-dimensional materials on the fabric," said Dr Felice Torrisi of the Cambridge Graphene Centre, the paper's senior author.
"Digital textile printing has been around for decades to print simple colorants on textiles, but our result demonstrates for the first time that such technology can also be used to print the entire electronic integrated circuits on textiles," said co-author Professor Roman Sordan of Politecnico di Milano. "Although we demonstrated very simple integrated circuits, 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 printed components are flexible, washable and require low power, essential requirements for applications in wearable electronics," said Ph.D. student Tian Carey, the paper's first author.
This research opens a number of commercial opportunities for 2D material inks, ranging from personal health and well-being technology to wearable energy harvesting and storage, military garments, wearable computing and fashion.
"Turning textile fibers 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, such as displays or sensors and become interactive."
The use of graphene and other related 2D material (GRM) inks to create electronic components and devices integrated into fabrics and innovative textiles is at the center of new technical advances in the smart textiles industry. The teams at Cambridge Graphene Center and Politecnico di Milano are also involved in the Graphene Flagship; an EC-funded, pan-European project dedicated to bringing graphene and GRM technologies to commercial applications.
The paper on this research was published in Nature Communications.