This thesis presents a new approach for fabricating free standing structures on flexible substrates using the screen printing technique. The research addresses electronic textile applications and is intended to provide a new method for realising sensors and complex structures on fabrics. Conventional smart fabric fabrication methods, such as weaving and knitting, are only able to achieve planar structures with limited functionality. Packaged discrete sensors can also be attached directly to fabrics but this approach is unreliable and unsuitable for mass production. The reported materials and the fabrication processes enable free standing structures to be formed by printing functional layers directly on top of the fabric. This reduces the fabrication complexity and increases wearer comfort and the flexibility of the fabric. This research details an investigation into sacrificial materials suitable for use on fabrics. A plastic crystalline material (Trimetlylolethane (TME)) was identified as an appropriate sacrificial material because it sublimates which reduces the chance of stiction occurring. A screen printable TME paste has been achieved by dissolving TME powder in a solvent mixture of cyclohexanol (CH) and propylene glycol (PG). The TME sacrificial paste can be cured at 85 oC for 5 minutes providing a solid foundation for subsequent printed layers. This sacrificial layer can be removed in 30 minutes at 150 oC leaving no residue. EFV4/4965 UV curable dielectric material was identified as an appropriate structural material for use with TME. The feasibility of the sacrificial and structural materials has been demonstrated by the fabrication of free standing cantilevers and microfluidic pumps on fabrics and flexible plastic films. Printed cantilevers, with capacitive and piezoelectric sensing mechanisms, have been demonstrated as human motion sensors. A printed microfluidic pump with a maximum pumping rate of 68 μL/min at 3 kHz has also been demonstrated. Both the cantilever and micropump have been demonstrated, for the first time, on fabrics and polyimide substrates, respectively.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:588892 |
| Date | January 2013 |
| Creators | Wei, Yang |
| Contributors | Tudor, Michael |
| Publisher | University of Southampton |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://eprints.soton.ac.uk/360759/ |
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