Scientists from the UC Berkeley in California lwa have ultra-thin material has been developed that other colors reflect at bending. The film of silicon would ever can be used for almost invisible cracks to be detected in, for example, bridges, buildings or airplanes.
The film makes use of a new approach to color to change. This method is based on the modification of the surface to various visible wavelengths and to reflect instead of changing the chemical composition of a material. In the semiconductor material of 120nm thick ribs and rods are etched thinner than a single wave of light. Each obstacle in the film is designed to allow a certain wavelength of light to reflect. By the film to bend or stretch, reflects the film other colors.
The first piece of material was only a square inch, but one of the researchers says that there are already several options for also larger surfaces of the material to produce within the existing semiconductor industry. Once you have that, hope the researchers applications. They think in the first instance, to sensors that change colour when, for example, metal fatigue, but also to the entertainment industry, and security sectors there may make use of.
This way to different colors to ‘make it’ is also to be found in nature. Certain butterflies and beetles, change as color. The scientists developed the material reflects up to 83 percent of the incoming light and change color when a curve of the 25nm. The color shift in the prototype goes from green to yellow, orange and red about 39nm of wavelengths. Further research should also set the number of colors increase.
The paper of the study is available on Monday online on the site of the scientific journal Optics.
