Vantablack – The black that makes objects ‘disappear’
In the Science Museum in London, behind a glass panel, stands a bust of a man. It is the face of BBC presenter Marty Jopson. The statue is highly textured, and the light skilfully plays across his wrinkles and dimples. Apart from the upturned tips of Jopson’s moustache, there is nothing particularly striking about this bust. Next to it, however, stands an identical bust that baffles the mind. It looks as though someone has cut a hole in the air in the shape of Jopson’s head. Visitors see only a gaping, empty blackness. The texture of the face dissolves into a velvety mass. Only from the side can one tell that the bust has any depth at all. What is on display is the phenomenon known as Vantablack.
What is Vantablack?
The name Vantablack stands for ‘Vertically Aligned Carbon Nanotube Arrays’. Whilst most black inks and coatings reflect enough light for the eye to distinguish texture and dimension, Vantablack is so black that it renders the object as practically two-dimensional to the observer. Vantablack is therefore the darkest coating currently known to us. This coating consists of millions of tiny nanotubes, each 10,000 times thinner than a human hair. It is precisely these nanotubes that enable the coating to absorb 99.965 per cent of the incident light.
What does this type of coating look like?
Steve Northam, Director of Business Development, describes Vantablack as a forest of trees three kilometres tall, with plenty of space between them. Light enters, bounces off the trees and is absorbed. A coating that is practically invisible in the dark, even when a torch is shone directly on it.
The difference between Vantablack and colours
Colour, as we humans perceive it, is the result of how light is reflected by an object. Different light frequencies produce different colours. Vantablack is not a colour, but a material. According to Surrey NanoSystems, a surface area of one square centimetre contains around 1,000 million nanotubes. When light hits the tubes, it is absorbed and cannot escape. Put simply, this means that Vantablack is actually the absence of colour. For this reason, you cannot simply buy a bucket of it, dip a brush in and apply Vantablack to your walls. It has to be produced in the Surrey NanoSystems laboratory using a complex (and patented) process involving several machines, multiple layers of different substances and extreme heat. From start to finish, applying Vantablack to an object can take up to two days. One gram of Vantablack is therefore much more expensive than the same amount of diamonds or gold.
Vantablack in everyday life
Unfortunately, it is not possible to use Vantablack in everyday life, as the nanotubes are so small and thin that they collapse under the weight of human touch. You can imagine the surface as a field of wheat, where each stalk of wheat is about 100 metres tall. The stalks are very long in comparison to their diameter and remain upright even in strong winds, but if an aeroplane were to land on them, it would cause an irreparable dent. Vantablack is therefore susceptible to damage, which is why it cannot yet be applied to unprotected surfaces such as cars or high-end clothing – even the slightest touch would be enough for the material to lose its magic.
The applications of Vantablack
The possibilities for real-world applications are quite exciting. Vantablack is used in particular for calibration systems in space telescopes. Furthermore, whilst the material is touch-sensitive, it is extremely robust against other forces such as impacts and vibrations. This is because each carbon nanotube is unique and has almost no mass. The coatings also consist largely of air. This makes Vantablack ideal for protected objects that may have to withstand a bumpy ride, such as a space launch.
Whilst the aerospace industry is already using the coating, there is significant demand from a wide range of interested parties. From casino owners to celebrities, everyone wants this unique coating on their dice or even their luxury sports cars.
We are, of course, very keen to see where and how we will see this unique technology next. Even if we won’t be encountering Vantablack in our everyday lives in the near future, the new applications are certainly innovative and promising.
