A Japanese research team including the National Institute of Advanced Industrial Science and Technology (AIST) announced April 24 that it has developed a rubber sheet that absorbs almost 100 percent of light.
The rubber sheet is durable and could be used in devices such as telescopes and cameras to prevent the irregular reflection of light, as well as in ornaments and artworks that need a beautiful black, the research team said.
The sheet is made of silicone rubber mixed with carbon, which absorbs light. Its surface is embossed with micro-conus arrays, about 0.05 millimeters high, and light is trapped in between the valleys of cones, with very little reflected out.
The absorption rate is more than 99.5 percent of all light, while the percentage for commercially available black coating material is said to range from 97 to 98 percent. Specifically, it absorbs 99.6 to 99.7 percent of visible radiation, and more than 99.9 percent of some infrared ray radiation.
Material with an absorption rate of more than 99.9 percent has been developed in some countries, but it uses a carbon material whose surface breaks when touched. The AIST sheet is made of flexible silicone rubber, so its performance will not be compromised when it is touched or bent.
AIST group chief Kuniaki Amemiya, 43, said: “Because the sheet is made of common materials, it may be commercially available in the future. We want to improve the performance.”