Wrinkled aluminium foil with a portion—equally wrinkled—coated in Vantablack[3]
Vantablack is a class of super-black coatings with total hemispherical reflectances (THR) below 1%[4] in the visible spectrum. The name is a combination of the acronym VANTA (vertically aligned nanotube arrays)[5] and the shade black.
The original Vantablack coating was grown from a chemical vapour deposition process (CVD) and is claimed to be the "world's darkest material" absorbing up to 99.965% of visible light measured perpendicular to the material.[6][7] The coatings are unique in that they are super-black and retain uniform light absorption from almost all viewing angles. Original CVD Vantablack is no longer manufactured for commercial applications as it has been superseded by Vantablack spray coatings that offer similar optical performance in key parts of the electromagnetic spectrum.[8]
History
Ben Jensen, founder and CTO of Surrey NanoSystems, invented the coatings, which were publicly unveiled in July 2014,[9] and eventually commercialized by the scientific team from Surrey NanoSystems.
As of 2022[update], Vantablack coatings are very costly, and Surrey NanoSystems refuses to supply them to private individuals. Samples are provided only for applications they deem "valid".[14] Several other firms also distribute vertically aligned nanotube arrays, including NanoLab,[15] Santa Barbara Infrared[16] and others.[17]
Commercial production
The first orders were delivered in July 2014.[17] In 2015, production was scaled up to meet demand in the aerospace and defense sectors.[citation needed]
Controversy
Controversy arose when Surrey Nanosystems granted Anish Kapoor exclusive rights to use Vantablack in artistic applications.[18] Many artists voiced opposition to his monopoly over the substance.[19]
In response, Nanolab, a Waltham, Massachusetts-based carbon nanotube manufacturer, partnered with Boston artist Jason Chase to release a nanotube-based black paint called Singularity Black.[20] During the first showing of the colour, Chase, alluding to Vantablack, stated that "its possibilities have been stunted by not being available to experiment with", and Singularity Black's release was important to create access.[21][22]
Visual characteristics
As Vantablack is composed of carbon nanotubes that absorb exceptionally high levels of visible light, it is widely considered one of the darkest pigments created. When applied to three-dimensional objects, Vantablack produces the appearance of a two-dimensional surface or void space.[23]
Properties
Vantablack grown on metal foil
CVD Vantablack is composed of a forest of vertical carbon nanotubes "grown" on a substrate using a modified chemical vapor deposition process. When light strikes Vantablack, instead of bouncing off, it becomes trapped and continually deflected amongst the tubes, absorbed, and eventually dissipated as heat.[24]
CVD Vantablack was an improvement over similar substances developed at the time. Vantablack absorbs up to 99.965% of visible light and can be created at 400 °C (752 °F). NASA had previously developed a similar substance that was grown at 750 °C (1,380 °F), which required materials to be more heat resistant than Vantablack.[24] Darker materials are possible: in 2019, MIT engineers developed a CVD material which reflects a tenth of the amount of light that Vantablack reflects.[25]
The outgassing and particle fallout levels of Vantablack are low compared to similar substances, which makes it more commercially viable. Vantablack is resistant to mechanical vibration and exhibits thermal stability.[26]
Applications
As one of the darkest materials, Vantablack has many potential applications, such as preventing stray light from entering telescopes, and improving the performance of infrared cameras both on Earth and in space.[17] Surfaces coated with Vantablack are highly suitable for emitting and absorbing blackbody radiation. These coatings possess suitable durability, which enables them to perform well in diverse temperature ranges and environments such as vacuum and air applications. Consequently, using Vantablack coatings in optical configurations can enhance their overall performance.[27]
In addition to directly growing aligned carbon nanotubes, Vantablack is made into two sprayable paints with randomly oriented nanotubes, Vantablack S-VIS and Vantablack S-IR with better infrared absorption than the former. These paints require a special license, a temperature of 100–280 °C, and vacuum post-processing.[28] Surrey NanoSystems also markets a line of non-nanotube sprayable paints known as Vantablack VBx that are even easier to apply.[29]
Vantablack has also sparked interest from the scientific community for use in cameras and sensors. Its distinctive characteristics make it a desirable material for cinema projectors, lenses, luxury products, and design items. Furthermore, its light-absorbing properties have the potential to improve the efficiency of solar panels and cells.[30]
Vantablack S-VIS, a sprayable paint that uses randomly aligned carbon nanotubes and very high levels of absorption from ultraviolet to the terahertz spectrum, has been exclusively licensed to Anish Kapoor's studio for artistic use.[31]
The manufacturer claims that Vantablack is subject to export controls by the UK.[citation needed] Due to its physical requirements and thermal characteristics, the original Vantablack is not practical for use in many types of art.[32]
Vantablack VBx2, a variant of the non-nanotube Vantablack VBx that is optimized for large area spraying, was used in a "Vantablack pavilion" at the 2018 Winter Olympics.[33]
In September 2019, BMW unveiled an X6 concept with Vantablack paint at the International Motor Show Germany; however, the company does not plan on producing the color on production models of the X6.[36]
French musician Gesaffelstein used Vantablack VBx2 as part of his stage decoration during his Coachella 2019 performance.[37][38]
^Theocharous, E.; Deshpande, R.; Dillon, A. C.; Lehman, J. (2006). "Evaluation of a pyroelectric detector with a carbon multiwalled nanotube black coating in the infrared". Applied Optics. 45 (6): 1093–7. Bibcode:2006ApOpt..45.1093T. doi:10.1364/AO.45.001093. PMID16523768.
^Theocharous, S.P.; Theocharous, E.; Lehman, J.H. (2012). "The evaluation of the performance of two pyroelectric detectors with vertically aligned multi-walled carbon nanotube coatings". Infrared Physics & Technology. 55 (4): 299–305. Bibcode:2012InPhT..55..299T. doi:10.1016/j.infrared.2012.03.006.
