A dual-frequency liquid crystal smart window with adjustable active and passive modes that utilize thermally responsive chiral molecules.
Zheng-Wei Lu1, Zhen-Yi Huang1*, Wei Lee2
1Institute of Photonic System, College of Photonics, National Yang Ming Chiao Tung University, Tainan, Taiwan
2Institute of Imaging and Biomedical Photonics, College of Photonics, National Yang Ming Chiao Tung University, Tainan, Taiwan
* Presenter:Zhen-Yi Huang, email:qiip76@gmail.com
We have developed a smart window based on cholesteric liquid crystal (CLC) that integrates both passive and active control mechanisms. This window can reversibly switch between high- and low-transmission states as the ambient temperature changes. Our design features a thermosensitized CLC that exhibits weak left-handed chirality at low temperatures, which increases as the temperature rises. This is achieved by mixing a thermosensitive chiral dopant (TCD) and a left-handed chiral dopant (S811) in dual-frequency liquid crystal (DFLC). The resulting change in chirality alters the thickness-to-pitch ratio (d/p), changing the CLC texture from the homeotropic (H) to fingerprint (FP) state. In addition, the incorporation of a dichroic dye enhances the optical contrast between the high-transmission H texture and the low-transmission FP texture. The dielectric anisotropy in the DFLC can be flexibly adjusted, enabling precise control of the switching temperature and transmission at different frequencies. This technological advancement significantly increases the flexibility and tunability of smart window, with great potential for energy saving and environmental control applications.


Keywords: Smart Window, Thermosensitive Chiral Dopants, Dual-Frequency Liquid Crystal