The new study, with input from the universities of Exeter, Cambridge, Leeds and Bath, describes and tests a new sustainable approach for fully inkjet-printed, eco-friendly e-textiles named Smart, Wearable, and Eco-friendly Electronic Textiles (SWEET). Their findings are published in Energy and Environmental Materials.
E-textiles are textiles embedded with electronic components such as sensors, batteries or lights that can be used in fashion apparel, performance sportwear, or for garments that monitor people’s vital signs. Such textiles need to be durable, safe to wear, comfortable, and environmentally benign when no longer required.
In a statement, study leader Professor Nazmul Karim at Southampton University’s Winchester School of Art said: “Integrating electrical components into conventional textiles complicates the recycling of the material because it often contains metals, such as silver, that don’t easily biodegrade. Our potential eco-friendly approach for selecting sustainable materials and manufacturing overcomes this, enabling the fabric to decompose when it is disposed of.”
The team’s design has a sensing layer, a layer to interface with the sensors, and a base fabric. It uses a textile called Tencel for the base, which is made from wood and is biodegradable. The active electronics in the design are made from graphene, along with the polymer PEDOT: PSS. These conductive materials are precision inkjet-printed onto the fabric.
The researchers tested samples of the material for continuous monitoring of human physiology using five volunteers. Swatches of the fabric, connected to monitoring equipment, were attached to gloves worn by the participants and results confirmed the material can measure heart rate and temperature at industry standard.
Co-author Dr Shaila Afroj, an Associate Professor of Sustainable Materials from Exeter University, said: “Achieving reliable, industry-standard monitoring with eco-friendly materials is a significant milestone. It demonstrates that sustainability doesn’t have to come at the cost of functionality, especially in critical applications like healthcare.”
The project team then buried the e-textiles in soil to measure its biodegradable properties. After four months, the fabric had lost 48 per cent of its weight and 98 per cent of its strength, suggesting relatively rapid and effective decomposition. A life cycle assessment revealed the graphene-based electrodes had up to 40 times less impact on the environment than standard electrodes.
Marzia Dulal from UWE Bristol, a Commonwealth PhD Scholar and the first author of the study, said: “Our life cycle analysis shows that graphene-based e-textiles have a fraction of the environmental footprint compared to traditional electronics. This makes them a more responsible choice for industries looking to reduce their ecological impact.”
According to Southampton University, the ink-jet printing process is also a more sustainable approach for e-textile fabrications, depositing precise numbers of functional materials on textiles as needed, with almost no material waste and less use of water and energy than conventional screen printing.
Professor Karim said: “Amid rising pollution from landfill sites, our study helps to address a lack of research in the area of biodegradation of e-textiles. These materials will become increasingly more important in our lives, particularly in the area of healthcare, so it’s really important we consider how to make them more eco-friendly, both in their manufacturing and disposal.”
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