Technological development of liquid crystal smart window
Tsung-Hsien Lin1*
1Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan
* Presenter:Tsung-Hsien Lin,
Smart window is the films/glasses having the incredible feature of controlling heat, privacy, and getting their transmission properties changed from opaque to translucent to transparent under the influence of voltage. The flow of light and heat between indoor and outdoor is controllable, providing human life more convenient and comfortable. In order to achieve true energy conservation and versatility, it is highly desirable but challenging to design a single device capable of simultaneously modifying haze and tint as well as exhibiting multi-stability. We have developed a versatile tristate smart glass based on various liquid crystal modes. The smart glass can also be voltage-switchable among three field-free stable states of different optical transmission properties. With a different electrode configuration, such tristable switching can be achieved in cholesteric liquid crystals with Bragg reflections from near-ultraviolet to visible and near-infrared. By incorporating a dichroic dye into the CLC, we demonstrate a smart daylighting−privacy window based on the tristable optical switch, and both the tint and haze levels of the window are electrically switchable. We also make use of the Bragg reflection of planar-state CLC and explore the applicability of the tristable optical switch to full-color see-through displays. With the demonstrated versatility in design and outstanding field-off stability, it is anticipated that the LC smart glass can find widespread use, from intelligent control of lighting, building climate, and privacy to window displays for advertisement use and artistic design.

Keywords: liquid crystal, smart window, film