That bright, reflective coating used on road signs, bicycles and clothing are important safety measures at night. They help drivers get to their destinations while avoiding bicyclists and pedestrians in low-light conditions. Now, inspired by the structure of insect eyes, scientists have developed new materials that could improve the color and effectiveness of these safeguards. Their report appears in the ACS journal Langmuir.
Retroreflective materials, including some tapes and road paints, work by bouncing light back toward the original source, such as a car's headlights, making them bright and easy to see. Existing retroreflectors are usually made with glass microbeads and microprisms. Dyes, pigments or plastic layers are often added for color; however, they tend to reduce the reflection of light, and the colors can fade over time. Hongta Yang and colleagues turned to the compound eyes of insects for a new way to address these limitations.