Optically Transparent and Color-Stable Elastomer with Structural Coloration under Elongation

Optically transparent and colored elastomers with high toughness are expected to play an important role in the construction of advanced medical materials, wearable displays, and soft robots. In this study, we found that composite elastomers consisting of amorphous SiO₂ particles homogeneously dispersed in high concentrations within a biocompatible acrylic polymer network exhibit optical transparency and bright structural colors. In the composite elastomers, the system in which the SiO₂ particles form a colloidal amorphous array hardly changes its structural color hue despite deformation due to elongation. Furthermore, the composite elastomer of the SiO₂ particles with the acrylic polymer network also results in high mechanical toughness. In summary, we have shown that the elastomer that exhibits fade-resistant structural coloration formed from safe materials can combine stable coloration and mechanical strength independent of their shape. This is expected to have new potential in future technologies to support our daily life.