A new lab-created substance reflects almost no light, making it possibly the darkest material ever.
Scientists have created a new material that is most likely the darkest material on the planet. This metamaterial is made of an intricately constructed array of tiny silver wires that are embedded in aluminium oxide and reflects almost no light. When light waves hit it, the metamaterial bends them in odd ways and sends them in unnatural directions. Scientists say that this material may find its use in military applications, specifically in developing equipment invisible to radar.
New Scientist reports:
Metamaterials consist of a regular array of two or more tiny components, each smaller than the wavelengths of the light they interact with. It is this array-like internal structure that gives them their unusual properties.
Evgenii Narimanov of Purdue University in West Lafayette, Indiana, realised that it should be possible to design a metamaterial with the right internal structure to absorb virtually all the electromagnetic radiation in a particular range. An object made of such a material would effectively be perfectly black. By contrast, ordinary black objects always reflect a little light.
In collaboration with Narimanov, Mikhail Noginov and colleagues at Norfolk State University in Virginia have now created such a perfectly black material. It consists of silver wires 35 nanometres in diameter, embedded in 1-centimetre squares of aluminium oxide, 51 micrometres thick.
Image by Vanessa Pike-Russell