Randunu Devage Ishara Dharmasena1 Imalka Jayawardena1 Malaka Perera2 Maduka Chandrasiri2 Vivek Ramchandani2 Chris Mills1 Robert Dorey1 Ravi Silva1

1, University of Surrey, Guildford, , United Kingdom
2, MAS Innovations (Pvt) Limited, Biyagama, , Sri Lanka

The advent of smart materials systems and devices has revolutionized the world in recent years enhancing the sensing and communication capabilities with the aim of improving the standard of life. Wearable electronics, which combines electronic components into textiles for numerous applications, play a key role in this regard, while being considered a major component in the internet of things (IoT). One of the main challenges for wearable technologies is to ensure their autonomous operation via a renewable energy source, which can ideally be realized by scavenging energy from the surrounding.
Triboelectric nanogenerators (TENGs) convert mechanical movements into electricity via a combination of triboelectric effect and electrostatic induction, and are in the forefront of energy harvesting technologies. [1, 2] TENGs can act as energy harvesters as well as self-powered sensors, with a reputation for high outputs, high efficiency, simple construction, and low cost. [1] However, there is only a limited number of studies conducted on textile based TENG structures which can fulfil the requirements of a wearable system.
Herein, we present a new class of wearable TENGs composed of commonly used textile materials and processing techniques. The active triboelectric materials are deposited on both metallic, and non-metallic conductive core fabrics. The triboelectric layers are modified with different polymers and fibres, using techniques such as core-spinning, dip coating and spray coating. Different surface modification techniques commonly utilized in the textile industry are used to further improve TENG performance. These devices are capable of producing significant outputs, with maximum current density of around 100 µA/m2, voltage exceeding 20 V, and a power density of around 10 mW/m2 under low frequency periodic contact and separation movements.
In conclusion, this work introduces a new method of constructing efficient textile based wearable TENG structures with a high emphasis on preserving their wearable properties and improving the manufacturability at large scale, encompassing many potential applications.
1. Z.L. Wang, et al. Faraday discuss. 176 (2014) 447-458.
2. Dharmasena et. al., Energy Environ. Sci. 10 (2017), 1801-1811.