EPSRC-SFI: Next Generation Energy Autonomous Textile Fabrics based on Triboelectric Nanogenerators (NextGenT-TENG)

In recent years there has been a major surge in the use of wearable electronic devices & sensors (such as fitness monitors, smart watches, electrocardiogram (ECG) sensors etc.). The last decade has led to major advances in the capability of wearable systems; however, performance enhancement inevitably leads to miniaturisation of electronics meaning more sensors and increased power requirements going forward. At present, there is an urgent need to provide a sufficient and autonomous source of clean power to avoid dependence on cumbersome & environmentally unfriendly battery packs. The textile triboelectric nano generator (T-TENG) offers a solution. Triboelectric nano generators (TENGs) use the cyclic contact of two suitably chosen surfaces to convert mechanical energy to electrical energy. T-TENGs are simply TENGs where the tribo-contact materials are incorporated into wearable textiles capable of converting energy in human motions such as daily walking & arm movements into electricity. At present; however, T-TENG performance lags significantly behind that of conventional bulk TENGs and is insufficient to power most e-textile systems.
This project will develop a next generation of high performance textile triboelectric nano generator capable of meeting the current and future energy requirements of wearable systems. It will also develop technology to incorporate the T-TENG in fully integrated energy autonomous fabrics.
We will achieve this step-change in T-TENG performance via the following approach. First, the problem is intensely multidisciplinary and this has previously hampered development of a full picture. Therefore, this project unties the fields of electronic engineering, tribology, materials chemistry, and textiles technology to create the capability required to understand all key aspects of device performance. Next, recognising the need for a rigorous scientific foundation for device design, we will develop a fundamental understanding of the underlying physics of the tribo-contact of textiles. This will culminate in a predictive model for device performance accounting for both the mechanics and electrostatics of the T-TENG. We know that output is hugely linked to the amount of tribo-change density that can be developed at the interface. Here, we contend that maximising difference in election affinity (i.e. between the tribo-materials) and contact area will be critical. Therefore, we will optimise the materials, fibre architecture and surface topography of the textiles to maximise these two key parameters. On interface materials, we will implement the use of material pairs with maximum difference in electron affinity. This will take the form of metal oxide coated fibres in contact with conventional textile fibres such as polyester and polypropylene. On fibre architecture, we will use our predictive T-TENG model to design a fibre architecture that maximises contact area. On surface topography, we will pioneer the use of branching nano filaments or nano pillars to further enhance contact area. To implement these coatings and surface features on textile fabrics, the project will develop a number of novel processing techniques. All of these aspects will then be united in a single device design which will be further modified and refined. The optimised T-TENG will then be fully integrated with a textile based sensor system to form a fully energy autonomous fabric. Finally, a technology demonstrator will be built to demonstrate output performance to both academia & industry. We will work closely with our industrial partners Kyrima & Pireta who are both highly experienced in developing new technologies for the e-textiles industry. A successful outcome would mean that a host of wearable systems in the medical and entertainment sectors could be powered using a clean and free source of energy: that of simple everyday human motion.

The project will develop a next generation wearable textile triboelectric nano generator (T-TENG) technology capable of powering current & future wearable electronic devices & sensors. It will also develop the technology for realising energy autonomous sensing fabrics based on T-TENGs. The power requirements of wearable & portable systems is rising rapidly due to densification of electronics. The technology developed here will replace cumbersome battery packs and provide a continuous free source of energy derived from human movement. This will have a major impact on health & well-being as the new technology would be in a position to autonomously power a host of wearable medical & fitness devices and sensors from blood pressure monitors & pacemakers to movement sensors, pulse oximeters & continuous glucose monitors (CGMs). Thus, the technology (in conjunction with AI & machine learning) will play a key role in realising a personalised, preventative and connected health system based on patient monitoring and data collection which will improve outcomes and save money. The technology will also impact on quality of life more generally as it would also be a vital power source for emerging portable communications & entertainment devices such as smart watches & smart glasses. The UK is a leader in gaming & immersive technologies and the boundaries for these industries are also hugely governed by power supply issues. There are also major environmental benefits. Eliminating the need for environmentally harmful batteries and basing the power requirements of the wearables sector on a freely available clean source of power will contribute to a greener environment. The project contributes directly to solving the UK government's Faraday Challenge aimed at finding alternatives to conventional batteries.
The UK is home to a number of small & emerging e-textiles companies exploring new wearable technologies. A new T-TENG technology developed in the UK & Ireland would be a unique opportunity for these businesses to bring forward a new technology. In the first instance, this impact will benefit our project partners Pireta & Kymira who will have the opportunity to work towards the longer term goal of bringing the technology to market. The partners will gain access to valuable university research expertise that will provide immediate opportunities for growth. A wearable power source technology capable of enabling energy autonomous wearable electronic systems would clearly have enormous sales potential globally as the number of wearable devices sold globally is predicted to rise to 289 million by 2023. It has the potential to contribute to UK & Irish GDP & create jobs in the e-textiles sector. The project will uncover the key fundamental science of the T-TENG and develop the design & processing approaches required for industrial practitioners to develop & build similar technologies. In developing the technology, the project will produce a number of highly trained research engineers that will be ideally positioned to drive innovation within the UK & Irish e-textiles sector. The public and public bodies such as UK and Irish national health services (NHS & HSE) will benefit from the programme of engagement activities built into the proposal. This will result in a heightened level of awareness of the growing power requirements of wearable systems, their widespread applications and the possibility of a fully integrated energy autonomous solution via a next generation wearable T-TENG. This creation of technology awareness will ultimately lay the groundwork for uptake of the technology by the public and major stakeholder organisations such as the NHS/HSE. The project will also provide the evidence required to convince both industry & public bodies of the power capabilities of the new T-TENG device. The outcomes will provide an ideal platform for attracting funding & support for higher TRL research aimed at commercialisation.