A new material that is blacker than any black has been invented. The metamaterial absorbs any and all light. It's made up of silver wires 35 nanometres in diameter, embedded in 1-centimetre squares of aluminium oxide, 51 micrometres thick.
The team tested their handiwork by illuminating polished and roughened versions of the material with near-infrared radiation at a wavelength of around 900 nanometres, just beyond the red end of the visible spectrum. With the radiation hitting the material at an angle less than 45 degrees from the perpendicular, they found that 20 per cent of it was reflected if the surface was polished, though the proportion dropped to less than 1 per cent if it was roughened.