The Department of Physics is delighted to welcome Prof Monica Craciun (University of Exeter) to give the ninth Physics Department Colloquium of Semester 2 2023/24. Please join us to listen to Prof Monica Craciun's seminar titled 'Integration of 2D materials with textiles for applications in wearable electronics'.

A reception will be held directly after the seminar, where tea and coffee will be provided.

The seminar is open to anyone from the university, students are encouraged to attend.

Title

Integration of 2D materials with textiles for applications in wearable electronics

Abstract

2D materials, with exceptional electrical conductivity and mechanical flexibility, are emerging systems for wearable electronics and smart textiles, offering opportunities for the seamless incorporation of electronic devices in textiles. I will give an overview of our progress in integrating 2D materials with textile substrates, encompassing fibres and fabrics, for a range of textile electronics applications. We demonstrated a versatile technique for coating common insulating textile fibres with monolayer and few-layer graphene produced through Chemical Vapor Deposition (CVD). Various fibre materials, including polypropylene, polylactic acid, polyethylene, and nylon, exhibited sheet resistance values as low as 600 Ohm sq−1, highlighting that the exceptional conductivity of graphene remains intact when applied to textile fibres. These graphene conductive fibres served as a foundation for integrating electronic devices directly within textiles. For instance, we demonstrated touch-sensitive and light-emitting functionalities in graphene electronic textile fibres. Additionally, the weaving of these fibres into fabrics facilitated the creation of display pixels and position-sensitive features. Finally, we showcased the use of graphene-coated polypropylene fibres as temperature sensors within a low-voltage carbon–graphene e-textile system. In the area of fabric-based wearable devices, a pivotal obstacle lies in seamlessly integrating electronics into fabrics while preserving their softness and comfort. A crucial aspect involves achieving electrically conductive coatings on textiles that adapt to the irregular and coarse structures of fabrics without compromising their properties. We introduced a straightforward, cost-effective, and highly scalable method, the ultrasonic spray coating. This technique was effectively used to coat various types of textile fabrics such as meta-aramid, polyester, and nylon using water-based suspension of graphene and create fabric electrodes displaying good conductivity, and resilience to bending, compression and tension. We further demonstrated the application of these graphene conductive fabric electrodes in self-powered sensing technologies embedded in textiles. The steppingstone for these advances is a new class of triboelectric energy harvesters able to convert presently unused sources from our living environment such as sounds and vibrations into electrical energy. Due to the conformation ability of the triboelectric sensors, they were implemented on key moving parts of the human body and used to monitor biomechanical motion through electrical signals. The self-powered sensors demonstrate their potential for wearable bioelectronics, intelligent robotics, prostheses, and rehabilitation purposes. Finally, we also demonstrated the use of CVD multilayer graphene on fabrics for a novel textile-integrated triboelectric nanogenerator capable of sensing and harvesting low-frequency acoustic energy.