VantablackÂ® is a super-black coating that holds the world record as the darkest man-made substance. It is the darkest material ever measured by the UK’s National Physical Laboratory, reflecting only 0.036% of the light that strikes it (measured at 700nm). It is currently available in two versions, either directly applied to surfaces using vacuum-deposition technology or by spraying and then post-processing.
Vantablack is not a black paint, pigment or fabric, but is instead a functionalized â€˜forestâ€™ of millions upon millions of incredibly small tubes made of carbon, or carbon nanotubes. Each nanotube in the ‘Vantablack forest’ has a diameter of around 20 nanometres (thatâ€™s about 3,500 times smaller than the diameter of the average human hair), and are typically from around 14 microns to 50 microns long. A surface area of 1 cm2 would contain around a billion nanotubes.
So how dark is it really? Video seems to capture its darkness best. Check out the four YouTube videos embedded below:
Lasers don’t reflect..
Ultra low reflectance: Vantablack absorbs 99.965% of light (750nm wavelength)
UV, Visible and IR absorption: Absorption works from UV (200-350 nm wavelength), through the visible (350-700nm) and into the far infrared (>16 microns) spectrum, with no spectral features
Very high front to back thermal conduction: excellent for Black Body calibration sources
Super hydrophobic: Unlike other black coatings, water has no impact on the optical properties
Very high thermal shock resistance: Repeatedly plunging a Vantablack coated substrate into liquid Nitrogen at -196Â°C and then transferring to a 300Â°C hot plate in air does not affect its properties.
Resistant to extreme shock and vibration: Independently tested, Vantablack has been subjected to severe shocks and vibration simulating launch and staging.
Low outgassing and mass loss: Independent testing to ECSS shows almost undetectable levels of outgassing, CVCM, WVR, RML and TML
Excellent BDRF and TIS performance: Even at shallow angles the levels of blackness outperforms all other commercial super-black coatings
Why is it so dark?
Light energy striking the Vantablack surface enters the space between the nanotubes and is rapidly absorbed as it â€˜bouncesâ€™ from tube to tube and simply cannot escape as the tubes are so long in relation to their diameter and the space between them. The near total lack of reflectance creates an almost perfect black surface. To understand this effect, try to visualise walking through a forest in which the trees are around 3km tall instead of the usual 10 to 20 metres. Itâ€™s easy to imagine just how little light, if any, would reach you. [source]
How is Vantablack made?
Vantablack is actually â€œgrownâ€ in a specially designed Chemical Vapour Deposition chamber under an array of powerful lamps that raise the surface temperature to 430ÂºC or higher to allow the nanotube forest to grow. So light itself is used in the production of the worldâ€™s darkest substance! A sprayable version of Vantablack is also available, called Vantablack S-VIS. [source]