Elastic Structure Color Material “Photonic Rubber” That Changes Color Due to Deformation

Abstract

A lot of novel elastic materials with tunable structural color by combine soft material and structural color have been reported in the past two decades. A typical example, colloidal crystals enable change structural color by deforming the particle spacing of the crystal lattice. We have proposed that elastic materials called photonic rubber to change their structural color due to tension (stretching), compression, and expansion due to external stress. One diffraction peak is observed in the reflection spectrum from a high-quality colloidal crystal oriented uniaxially. Since the diffraction peak shifts due to stress, application as a sensor is expected by utilizing the relationship between the shift amount and stress. We have investigated the basic characteristics of stretching, compression, and expansion of photonic rubber. Currently, we are conducting research for practical use. Regarding durability, there was no significant deterioration in the structural color change in the tensile test due to reciprocating motion exceeding 100 000 times. On the other hand, we are addressing more practical issues related to manufacturing costs, such as increasing the size of homogeneous colloidal crystals and increasing the rate of film formation.