Carbon nanotube forest camouflages 3-D objects
L. J. Guo et al, University of Michigan/Applied Physics Letters
The refractive index of a material is a measure of how much that material slows down light, and carbon nanotube "forests" have a low index of refraction very close to that of air. Since the two materials affect the passage of light in similar ways, there is little reflection and scattering of light as it passes from air into a layer of nanotubes.
The Michigan team realized they could use this property to visually hide the structure of objects. As described in the AIP's journal Applied Physics Letters, the scientists manufactured a 3-D image of a tank out of silicon. When the image was illuminated with white light, reflections revealed the tank's contours, but after the researchers grew a forest of carbon nanotubes on top of the tank, the light was soaked up by the tank's coating, revealing nothing more than a black sheet.
By absorbing instead of scattering light, carbon nanotube coatings could cloak an object against a black background, such as that of deep space, the researchers note. In such cases the carbon nanotube forest "acts as a perfect magic black cloth that can completely conceal the 3-D structure of the object," the researchers write.
Original publication
Haofei Shi, Jong G. Ok, Hyoung Won Baac, and L. Jay Guo; "Low density carbon nanotube forest as an index-matched and near perfect absorption coating"; is accepted for publication in Applied Physics Letters.
Most read news
Original publication
Haofei Shi, Jong G. Ok, Hyoung Won Baac, and L. Jay Guo; "Low density carbon nanotube forest as an index-matched and near perfect absorption coating"; is accepted for publication in Applied Physics Letters.
Organizations
Other news from the department science
Get the chemical industry in your inbox
From now on, don't miss a thing: Our newsletter for the chemical industry, analytics, lab technology and process engineering brings you up to date every Tuesday and Thursday. The latest industry news, product highlights and innovations - compact and easy to understand in your inbox. Researched by us so you don't have to.