Textile-based wearable electronics, as the next generation of wearable devices, have attracted considerable interest. Conductive fibres are the building blocks for developing these flexible and wearable devices. Electroless deposition (ELD) is a traditional method to deposit metal nanoparticles on different materials by autocatalytic chemical reduction of metal cations in a liquid bath. However, there are no catalytic sites on the fibre surface to initiate the ELD. To solve this problem, this research aims to coat polyphenols including dopamine, tannic acid and curcumin on the fibre surface via pi-pi stacking and then served as the platform to capture catalysts via cation-pi interaction for depositing metal nanoparticles on fibres. By introducing the polyphenols-assisted ELD, conductive yarns and fabrics were obtained and the resistance of Ni-coated cotton yarns reached 0. 05 ohm/cm. The fibre interface molecular engineering provided strong adhesion forces between the metal layer and the fibre surface, resulting in durable metal-coated yarns and fabrics. On the other hand, the surface morphology of metal deposits on fibres was controlled in nanoscale by adjusting the ELD time to yield the metal coatings with multilayers shape on fibre surface in which unfilled gaps between metal nanoparticles prevented the metal films from cracking under bending. In addition, the Kelvin structure model was proposed to illustrate the relationship between the conductivity and flexibility of metal-plated fabrics. As a result, the normalised resistance of Ni-deposited fabrics (20 min ELD) was only 1.6 after 1000 mechanical bending cycles (bending radius = 0.1 mm). To construct these metallised substrates into wearable sensors, the fibrous structure was utilised. Based on the change of fibre-to-fibre contacts in metal-coated yarns and 3D fibrous sponges under mechanical deformations, fibre-shaped wearable electronics including finger bending sensors, arm bending sensors, pressure sensors, touch sensors and human-machine interfaces for monitoring human motions were obtained by collecting different resistance values. The research indicated that polyphenols-assisted ELD can metallise other flexible substrates and extend the applications of conductive and flexible samples.
Date of Award | 31 Dec 2021 |
---|
Original language | English |
---|
Awarding Institution | - The University of Manchester
|
---|
Supervisor | Xuqing Liu (Supervisor) & Yi Li (Supervisor) |
---|
- Sensors
- Electroless deposition
- Molecular engineering
- Fibres
- Wearable electronics
Fibre Interface Molecular Engineering for Textile-based Wearable Electronics
Zhu, C. (Author). 31 Dec 2021
Student thesis: Phd