Abstract
Based on liquid crystal networks we developed 'smart' coatings with responsive surface topographies. Either by prepatterning or by the formation of self-organized structures they can be switched on and off in a pre-designed manner. Here we provide an overview of our methods to generate coatings that form surface structures upon the actuation by light. The coating oscillates between a flat surface and a surface with pre-designed 3D micro-patterns by modulating a light source. With recent developments in solid state lighting, light is an attractive trigger medium as it can be integrated in a device for local control or can be used remotely for flood or localized exposure. The basic principle of formation of surface topographies is based on the change of molecular organization in ordered liquid crystal polymer networks. The change in order leads to anisotropic dimensional changes with contraction along the director and expansion to the two perpendicular directions and an increase in volume by the formation of free volume. These two effects work in concert to provide local expansion and contraction in the coating steered by the local direction of molecular orientation. The surface deformation, expressed as the height difference between the activated regions and the non-activated regions divided by the initial film thickness, is of the order of 20%. Switching occurs immediately when the light is switched 'on' and 'off' and takes several tens of seconds.
Original language | English |
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Title of host publication | Emerging Liquid Crystal Technologies X |
Editors | L.-C. Chien, H.J. Coles, H. Kikuchi, I.I. Smalyukh |
Publisher | SPIE |
ISBN (Print) | 9781628414745 |
DOIs | |
Publication status | Published - 2015 |
Event | 10th Emerging Liquid Crystal Technologies Conference (ELCT 2015) - San Francisco, United States Duration: 9 Feb 2015 → 11 Feb 2015 Conference number: 10 |
Publication series
Name | Proceedings of SPIE |
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Publisher | SPIE: The International Society for Optical Engineering |
Volume | 9384 |
Conference
Conference | 10th Emerging Liquid Crystal Technologies Conference (ELCT 2015) |
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Abbreviated title | ELCT 2015 |
Country/Territory | United States |
City | San Francisco |
Period | 9/02/15 → 11/02/15 |
Keywords
- Dynamic
- Liquid crystal polymer networks
- Reversible
- Self-organizing
- Surface topographies