Changing Colors is an interactive exhibit that shows how some high-tech nanomaterials mimic natural phenomena. Super-small, light-reflecting structures—instead of pigments—on the wings of some butterflies create intense, iridescent colors. Nanoscientists have replicated this effect with layered, super-thin films. Watch the colors change on butterfly wings and thin-film slides as you move them beneath a light source, and discover how nanoscale structures can manipulate light and create color. Butterfly specimens deteriorate with heavy use, and may need to be replaced periodically.
Air bubbles trapped beneath a silicon crystal film are shown in this optical microscope image. Light passing through the bubbles creates the circular patterns and colors.
Extremely thin films like these have important electrical properties and therefore find numerous applications in ultra-fast computer chips and high-yield solar cells. This image shows an intermediate stage of their production; trapped air bubbles are removed in later processing.
• SIZE: The sample imaged is 27 nm thick and a few cm wide.
• IMAGING TOOL: Optical Microscope
"Exploring Materials - Thin Films" is a hands-on activity in which visitors create a colorful bookmark using a super thin layer of nail polish on water. They learn that a thin film creates iridescent, rainbow colors.