Peacock feathers are According to a paper published in the journal Scientific Reports, their bright iridescent colors proved to be very admirable, but they also proved to emit laser light. According to the author, this is the first example of a bioagent cavity in the animal kingdom.
As mentioned earlier, the bright iridescent colors of things like peacock feathers and butterfly wings come from not any pigment molecules, but from their structure. For example, chitin scales in butterfly wings (polysaccharides shared by insects) are arranged like roof tiles. Essentially, they form diffraction gratings, except that the photonic crystal produces only light of light or wavelengths, while the diffraction grating will produce the entire spectrum, just like a prism.
As far as peacock feathers are concerned, it is a conventional, periodic nanostructure of Barbules (fiber-like components, composed of keratin-coated melanin rods coated with orderly, which produce iridescent colors. Different colors correspond to different spacings of Barbules.
Both are examples of what physicists call natural occurrences of photonic crystals. Photonic crystals, also known as photonic bandgap materials, are “tunable”, meaning they are ordered accurately in a way that prevents light of certain wavelengths while allowing others to pass through. By changing the structure by changing the size of the tiles, the crystals are sensitive to different wavelengths. (In fact, rainbow weevils can control the size of their scales and how many chitin they are used to fine-tune as needed.)
Even better (from an application perspective), perception of color does not depend on perspective. Scales are not only for aesthetics; they help protect insects from elements. There are several types of artificial photonic crystals, but a better, more detailed understanding of how these structures grow in nature can help scientists design new materials with similar qualities, such as iridescent windows, self-cleaning surfaces of cars and buildings, and even waterproof textiles. Banknotes can incorporate encrypted iridescent patterns into foil making.
Everything from stained cattle bones and blue coral skeletons to insect wings, parrot feathers and human tissues, and salmon iris, from stained skeletons and blue coral skeletons to insect wings, blue coral skeletons to random laser emissions. The authors of this latest study are interested in whether they can use peacock feathers to generate similar laser emissions and hope to identify specific mechanisms.
Given their popularity for decorative and craft purposes, the authors did make sure that none of the feathers used in the experiments were impurities (such as dyes), but it was not difficult to raise peacock feathers. They cut off the barbs of what length they were and mounted the feathers on the absorbent substrate. They then injected the feathers into the feathers by placing the dye solution directly on them and letting them dry. In some cases, the feathers are stained multiple times. They then pump the sample with light pulses and measure any generated emissions.
The group observed laser emissions in all color areas of the feather eye spots in two different wavelengths, and the green area emitted the strongest laser light. However, they did not observe any laser emission from only one dyed feather emission, only in sample feathers that had undergone multiple wetting and complete drying cycles. This may be due to better diffusion of dyes and solvents into Babres, as well as possible loosening of the fibrils in the keratin sheath.
The authors were unable to determine the precise microstructure responsible for the laser. It doesn’t seem to be due to the keratin-coated melatonin rod. Nathan Dawson, co-author of Florida Tech, suggested to science that similar small structures in protein particles or feathers may act as laser cavity. He and his colleagues believe that one day their work could lead to the development of biocompatible lasers that can be safely embedded in the human body for perception, imaging and therapeutic purposes.
This story originally appeared in ARS Technica.
