Struktuurvärvid

Struktuurvärvid, also known as structural colors, are colors produced by the way light interacts with nanostructures rather than by pigments. These structures are typically microscopic or nanoscopic, meaning they are on the scale of the wavelength of visible light. When light strikes these precisely arranged physical structures, it is selectively reflected, refracted, or diffracted, resulting in the perception of color. Unlike pigmentary colors, which absorb certain wavelengths of light and reflect others, structural colors arise from the physical arrangement of materials.

The phenomenon is based on principles of thin-film interference, diffraction gratings, and photonic crystals. Thin-film interference occurs when light waves reflect off the top and bottom surfaces of a thin layer, interfering with each other to produce specific colors. Diffraction gratings, with their regularly spaced lines or grooves, scatter light into a spectrum of colors. Photonic crystals are three-dimensional structures that can control the flow of light in a manner analogous to how semiconductors control the flow of electrons.

Examples of structural colors are abundant in nature. The iridescent sheen of butterfly wings, peacock feathers, and the shells of some beetles are classic instances. The blue color of the sky and the rainbow colors seen in soap bubbles and oil slicks are also results of structural coloration, primarily through interference effects. Researchers are exploring structural colors for various applications, including advanced displays, paints, sensors, and anti-counterfeiting technologies, aiming to replicate these natural optical marvels for human use.