Nowadays, display and communication devices are supplementary items, many times posing transportation problems to the user, due to volume, weight and size, making them uncomfortable and inconvenient to use and carry. Current technology and innovation efforts look for alternative substrates, materials and ideas that eliminate or reduce much of these inconveniences. Products have been developed not only with reduced size and weight, but also improved flexibility. These products, including e-readers or rollable displays mimic more traditional forms of displaying information such as the information printed on paper. However, all of these applications are far from being fully integrated in basic objects of our society. This proposal seeks to establish a new ground-breaking technology for flexible, transparent, comfortable and easy to carry textile-embedded communication devices. The approach to realize this aim is to build the first fibre-embedded device with controllable light emission: a light-emitting transistor completely entrenched in a fabric. This will be achieved by combining organic semiconductors and dielectrics with graphene as conductive layer, in a novel concept that merges flexibility, transparency, optoelectronic properties and fabrication compatibility of these materials with textiles. Graphene and organic semiconductors combine mechanical flexibility and optical transparency with excellent electronic characteristics and low-temperature processing and are ideal for non-conventional substrates such as fibres of textiles. With just 3-4 Å thickness, monolayer graphene not only ensures high transparency, but it is bendable and stretchable. Together with its robustness and high conductivity, it is an extremely good candidate to replace current metallic electrodes. Polymers and organic small molecules, on the other hand, present a wide range of electrical behaviour, from conductors to insulators, with the possibility of solution processing. Several families of organic compounds present semiconductor behaviour and are successfully used in organic field-effect-transistors. Another advantage of organic materials is the possibility of chemical modification to add functionalities or change mechanical and optoelectronic properties. Such unique properties, allied with the potential that organic-semiconductor devices have demonstrated for display technology make it reasonable that a ground-break idea of wearable displays is achievable. The outputs of the proposed project, the development of textile-embedded optoelectronic devices, will be fundamental to the development of smart textiles as well as of transparent and flexible electronics. Achieving this goal is of strategic importance to secure a leading role of UK in these research fields. The results of this research are also likely to be of wide use in consumer applications. For instance, the project will allow the development of completely new approaches for integrated electronics and forms of displaying information, capable to be embedded into our everyday clothing. Since textiles are so present in society, the ability to embed display-based information and communication devices into wearable textiles would transform our clothing into mobile phones, displays with electronic newspapers or GPS-activated maps, and would certainly facilitate interactions and exchanges between individuals and communities. Such devices represent a radical alternative to conventional technologies as they must bend, stretch, compress, twist and deform into complex shapes while maintaining their levels of performance and reliability. Establishing the foundations for this future in electronics is also essential for other societal needs, such as biomedical monitoring, communication tools for the sensory impaired people, and personal security.

Monitoring vital signs is essential in healthcare, and although there are currently several ways of doing so, either at the hospital environment or at home, conventional devices pose different challenges to their users, being bulky and uncomfortable, often complicated to operate by non-experts, and extremely expensive. With the Internet-of-Things (IoT)-driven device connectivity and technological advancements, as cellular connectivity is replaced by other types of wireless communications like Bluetooth, the fast-growing market of connected wearables also plays an important role in the emerging market of remote patient monitoring, since wearable devices also enable a hands-free operation and continuous recording of useful data. Integrating sensors for body temperature, breathing rate and cardiac activity directly on textiles would eliminate the inconvenience of uncomfortable hardware directly in contact with the human skin. This is very important in the case of electrocardiography, particularly when performed continuously, which requires the prolonged use of gel electrolytes to reduce the resistance between the skin and the electrode, often causing allergies and skin irritation. In addition to measuring temperature, cardiac activity and breathing rate, wearable sensors can also be used to track a person's body movements, which can also find applications in different fields, such as physiotherapy and rehabilitation. For instance, gait patterns can provide a lot of information about a patient's health. Moreover, these body movements and wasted body heat are often underestimated as a means to generate energy to power wearable devices. This project aims to innovative develop graphene-based and self-powered vital signs sensors fully integrated on textiles and with wireless communication capabilities. Such sensors offer a comfortable and almost imperceptible way of continuous monitoring, as opposed to heavy and bulky equipment currently in use for the same purpose. Exposed to external stimuli, such as mechanical deformations or variations in temperature, the conductivity of these textiles will change in a predictable way, and this will be explored for sensing purposes. Furthermore, these conducting textiles will also be used as electrodes for electrocardiography. A self-contained and environmentally friendly energy source based on a triboelectric nanogenerator, capable of harvesting energy from the movements of the user, will also be developed using similar materials and methods. This innovative approach of building the sensors directly on textiles will put the UK in the forefront in the field of continuous vital sign monitoring and remote healthcare and has the potential to generate numerous business opportunities. Allied to self-monitoring and self-care, with the rise of remote health monitoring there is an increasing need of practical and convenient vital sign monitoring devices with sensors that can be self-powered, easily integrated with conventional electronics and wireless communications, and simply operated in the palm of our hands, for instance, using a mobile phone. To ensure that this project is carried out successfully, a team comprising the PI, 2 postgraduate research students (PGRS) and one experienced postdoctoral research associate (PDRA) will be assembled, and will work closely with two industrial partners with expertise in the textile industry, (Centexbel, Belgium and Heathcoat, UK), and two academic partners from Skoltech, Russia, with expertise in electronics and wireless communications, and UCL, UK, with expertise in data processing, ideal to complement the expertise in materials, nanotechnology and physics of the team at Exeter.