- Low reflection lenses, high reflection mirrors in devices such as better binoculars and telescopes, colour changing paints, and inks may now be powered by a newly discovered property of the interaction between light and molecules.
- Bengaluru based scientists have found that UV and blue light combination reversibly switches the system between 3D and 1D photonic structure — a novel interaction that can help make tunable and effective optical devices.
- In their quest to develop materials for tunable and effective optical devices, Scientists from the Centre for Nano and Soft Matter Sciences (CeNS), have discovered that
- high levels of light in the blue wavelengths or actinic light lead to switching between two photo isomers — Chiral Nematic (Ch) and Twist Grain Boundary Smectic C* (TGBC*)
- Which are liquid crystal phases possessing photonic structures in one and three dimensions, respectively.
- The change occurs because of interactions between light and molecules leading to photoisomerization in which light of a specific wavelength (actinic light) can bend molecules with certain linking groups.
- A well-known example in this regard involves a change in the shape of a macromolecule of azobenzene derivatives from essentially linear to highly bent form when irradiated with Ultraviolet light (~ 365 nm).
- The phenomenon found by the CeNS involves reverse transformation on stimulation with blue light.
- This phenomenon is quite attractive to achieve photo-driven isothermal phase transitions in liquid crystal (LC) materials.
- Such photoresponsive LCs are attractive for applications, including flexible polarisers, patterned objects, logic devices, and energy harvesting materials.
