The darkest material known to humans is called Vantablack. Developed by the company Surrey NanoSystems in the UK, Vantablack set a new record in 2014 for being the substance that absorbs the most light, reflecting almost none of it back to the eye. This results in an extremely dark black color that seems to just absorb any light that hits it. But since Vantablack was first developed, some new ultra-black materials have emerged that can absorb even more light. So is there anything that can beat Vantablack in terms of darkness?
What Makes a Material Ultra-Black?
A material appears black when it absorbs most visible light wavelengths and reflects very little back to the eye. The more light a material absorbs, the darker it will appear. Most “black” materials we encounter in everyday life are actually just very dark shades of gray, reflecting about 3-5% of light. True ultra-black materials reflect much less light – 0.05% or even less. Here are the factors that allow a material to achieve such a deep, dark black:
– Nanostructure – Materials with tiny nanoscale surface textures can trap and absorb light through extremely small cavities and channels. This prevents light from bouncing back off the surface.
– Low reflectivity – Flat, matte surfaces reflect less light than glossy or shiny ones. Ultra-black coatings are designed with very low innate reflectivity.
– Multiple light absorption – Using multiple layers and materials with different light absorbing properties maximizes absorption across the visible spectrum.
– Internal scattering – Materials that scatter light internally through chaotic reflections have less chance of light escaping back out.
– Light capturing dyes – Photo-absorbing dyes or pigments can convert light energy to heat rather than reflecting it back.
By optimizing all of these factors, ultra-black materials can get extremely close to a perfect black with 0% reflectivity. But is there anything darker than Vantablack yet?
What is Vantablack?
Vantablack is a coating comprised of vertically aligned carbon nanotube arrays. When light hits Vantablack, instead of bouncing off the surface, it becomes trapped inside the forest of carbon nanotubes and is continually deflected between the tiny carbon structures until it is absorbed and converted to heat.
| Vantablack Property | Measurement |
|---|---|
| Reflectance | 0.035% |
| Total hemispherical reflectance | 0.043% |
As the above measurements show, Vantablack absorbs over 99.96% of visible light, making it the darkest material ever measured when it was first introduced. This level of light absorption appears visually to the human eye as a “void” – a patch of utter and complete blackness into which all light seems to disappear. It’s been described as “staring into a hole cut into the universe”.
Vantablack Derivatives
Since the initial introduction of Vantablack in 2014, Surrey NanoSystems has continued to develop improved versions of the technology:
Vantablack S-VIS – The S-VIS version has a more sprayable formulation to make it easier to apply onto objects and not just flat surfaces. It absorbs up to 99.8% of visible light.
Vantablack VBx2 – Launched in 2019, VBx2 builds on the S-VIS version. It can be sprayed onto complex 3D objects and absorbs up to 99.96% of light, matching the original Vantablack.
Vantablack 2.0 – The newest iteration was announced in 2022. It incorporates an acrylic binding agent to improve adhesion and mechanical stability. Absorption remains up to 99.96%.
While the original Vantablack is still the darkest measured material, its derivatives match its performance in terms of light absorption. But have any other ultra-black materials surpassed Vantablack yet?
New Potential Record Holders
A few new ultra-black substances have emerged that may absorb even more light than Vantablack, though exact measurements are still pending:
Carbon Nanotube Forests – In 2019, researchers at the Massachusetts Institute of Technology grew forests of carbon nanotubes using a different technique than Surrey NanoSystems. Early measurements suggest it may absorb over 99.995% of light.
Superblack – A coating made of nickel phosphorous alloy that may absorb up to 99.97% of visible light. Still undergoing testing.
Black 3.0 – A Kickstarter project for an acrylic-based paint made of multiple black pigments. The developers claim a total reflectance under 0.5%.
Diatomaceous Carbon – Silicon dioxide particles extracted from algae skeletons can form a low density coating for deep blackness. Reflectance of 0.3-1.5% has been reported.
| Material | Estimated Light Absorption |
|---|---|
| Vantablack | 99.965% |
| MIT Carbon Nanotubes | 99.995%+ |
| Superblack | 99.97% |
While some of these materials may potentially exceed Vantablack in performance, they have not yet gone through the full testing and verification process to officially dethrone Vantablack as the darkest known substance. But they demonstrate the rapid pace of advancement in ultra-black coatings.
Uses of Ultra-Black Materials
Why develop such exceptionally dark materials? What are the applications and uses of these ultra-black coatings?
Optics and Sensors – Coating telescope lenses and space-based optical sensors reduces stray light for sharper imagery.
Art and Design – Sculptures and building surfaces coated in ultra-black create unique visual effects playing with light and shadow.
Fashion – Apparel and accessories use it for dramatic styling.
Solar Cells – Absorbing over 99% of light reduces reflection losses, improving efficiency.
Thermal Imaging – A purely black “reference point” improves calibration and sensitivity.
Military – For low visibility, covert operations sensors, tagging, aircraft, and equipment.
As ultra-black technology continues advancing, even more novel uses will emerge. Products integrating these coatings into designs and devices will drive consumer and industrial demand.
Manufacturing Ultra-Black Materials
Producing these ultra-black materials requires specialized laboratory equipment and techniques:
– Vacuum deposition – Utilizing vaporized carbon inside a vacuum chamber to deposit nanotube arrays onto a substrate.
– Chemical vapor deposition – Catalyzing carbon nanotube growth onto a surface exposed to hydrocarbon gases.
– 3D printing – Direct ink writing method to print intricate carbon nanotube structures.
– Layering – Sequentially depositing and bonding multiple layers of black materials together.
– Spraying – Formulating ultra-black particles into sprayable paints and coatings.
– Rolling – Using rollers to apply coatings onto large, flat surface areas.
– Functionalization – Adding surface treatments to optimize adhesion and environmental stability.
The high degree of control and customizability afforded by these fabrication methods lets researchers systematically test and optimize light absorption performance.
Challenges With Ultra-Black Materials
Despite their impressive light absorbing capabilities, some difficulties still remain with ultra-black substances:
– Fragility – The tiny nanostructures can be delicate and prone to scratching or breaking.
– Toxicity – Some manufacturing methods use volatile organic compounds or other toxic ingredients.
– Cost – The exotic fabrication techniques involved currently make these coatings very expensive.
– Imperfections – Achieving such consistent darkness across large surface areas is still difficult.
– Environmental stability – Conditions like humidity, UV light, and heat can degrade performance over time.
– Mechanical stability – Adhesion to surfaces and resistance to handling, flexing or impacts needs improvement.
Further refinement of production techniques and material engineering will help make these practical for more real-world functions.
Conclusion
While Vantablack still reigns as the darkest material ever characterized in a lab, emerging ultra-black technologies like MIT’s carbon nanotube forests suggest its record may soon be surpassed. Ongoing research into manufacturing methods, surface optimizations, and nanofabrication will unlock new levels of light absorption performance and expand the practical applications of ultra-black coatings. But for now, Vantablack remains the king of darkness against which all other ultra-black materials are compared.
