Applied Nanophotonics, Liquid Crystals and Biomedical Optics

Smart window devices have garnered significant attention recently. Traditional thermochromic windows can control infrared (IR) radiation but not visible light, whereas liquid crystals (LCs) control visibility through voltage-controlled scattering, neglecting IR control due to forward scattering. We demonstrate that nematic LCs with a minor concentration of nanoporous microparticles (NMPs) can rapidly modulate transparency in thin devices called NMP-LCs. To concurrently control both visible and IR spectra, we propose combining a layer of ultrashort pulsed laser-patterned vanadium dioxide (VO2) with a 2% NMP composite in the LC. The patterned VO2 film serves two key functions: (i) inducing LC alignment along the nanograting lines formed by pulsed laser patterning and (ii) enabling IR radiation control with enhanced thermochromic properties compared with closed structures. The LC component facilitates visibility control via voltage or temperature modulation. The combined system thus presents a superior smart window solution, capable of efficiently managing heat and visibility with high-speed response, low voltage requirements, and minimal LC and NMP concentrations.