A team from the University of Cambridge, with colleagues in Italy and China, have shown how graphene can be printed directly onto fabric to offer integrated electronic circuits that are comfortable to wear and can also last up to 20 cycles in a washing machine. Based on standard processing techniques, the work revealed how to incorporate washable, stretchable and breathable fully integrated electronic circuits directly onto fabric, with commercial potential for personal health and well-being technology, wearable energy harvesting and storage, as well as military clothing and wearable computing.
“Thanks to nanotechnology, in the future our clothes could incorporate…textile-based electronics, such as displays or sensors and become interactive”Felice Torrisi
In the study, which was based on previous work on the formulation of graphene inks for printed electronics, and described in Nature Communications [Carey et al. Nat. Commun. (2017) DOI: 10.1038/s41467-017-01210-2], the circuits were produced using low-cost, safe and environmentally friendly inks, while the printing was carried out based on standard inkjet printing techniques. With graphene and other related 2D material inks for electronic components and devices integrated into fabrics seen as crucial to progress in the smart textiles industry, the scalable inkjet printing was based on designing low-boiling point inks that could be printed directly onto polyester fabric.
The team also showed that altering the coarseness of the fabric helped to improve the performance of the printed devices. The versatility of the process allowed them to design single transistors and also all-printed integrated electronic circuits that have both active and passive components. Senior author Felice Torrisi said “Thanks to nanotechnology, in the future our clothes could incorporate…textile-based electronics, such as displays or sensors and become interactive”.
“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”Roman Sordan
Electronic devices currently fitted onto clothing depend on rigid, somewhat uncomfortable, electronic components mounted on plastic, rubber or textiles, and which are often limited in their compatibility with the skin, and become damaged when washed. The low quality of 2D material inks, as well as the complexity of the layered arrangement and a lack of a dielectric 2D material ink that can operate at room temperature and under strain, has been a constraint on the fabrication of electronic devices on textile with fully printed 2D heterostructures. They need robust and reproducible printed multi-layer stacks consisting of active channel, dielectric and conductive contact layers.
However, this new process is scalable and the team argue there are no big limitations to the development of wearable electronic devices as regards their complexity and performance. As co-author Roman Sordan said, “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”.