Mechano-chromic behavior of liquid photonic crystals

抄録

Photonic crystals have gained attention for their vivid colors, durability, and tunable properties. This study presents a novel mechano-chromic material composed of silica nanoparticles (SiO2NPs) forming liquid photonic crystals (LPCs) in water, encapsulated between two cover glasses. LPCs exhibit angle-dependent color that are sensible to mechanical deformation. Applying a normal force alters the lattice constant, shifting the dominant wavelength of the reflected light. SiO2NPs were synthesized using the Stöber method and assembled via centrifugation and ultrasonic dispersion. LPCs were characterized by UV-vis spectroscopy, dynamic light scattering, and SEM. Mechano-chromic behavior was analyzed with a micromanipulator and universal testing machine demonstrating a clear correlation between applied force and color change. This material showed a great potential for applications in pressure and surface stress sensing.