To enhance the flexibility of applying super-black coatings, Surrey NanoSystems has developed an IR optimised coating using the same technology developed for Vantablack S-VIS. This coating has the same mechanical, thermal and vacuum properties as Vantablack S-VIS, but has its optical performance improved from NIR to LWIR, and exceptional performance out to wavelengths of 300um. This allows optical designers to simplify baffle and lens design when accounting for stray light, critical for orbital sensing and aerospace flight systems where weight is at a premium.
Vantablack S-IR absorber coating is manufactured from short, non-aligned CNTs and other organic materials/binders dispersed in carrier solution. Once sprayed, it leaves behind a structured coating that is then subjected to further vacuum processing steps. This process functionalises and binds the coating structure together whilst forming optical cavities which trap light in a similar way to Vantablack S-VIS. It is so effective that its reflectance performance far outstrips any other known paint or commercial black coating in the infra-red spectrum - and it offers the second-lowest level of reflectance available today, bettered only by original Vantablack.
Vantablack S-IR technical specifications:
THR (total hemispherical reflectance) 0.2% at 700 nm
0.4% at 16um (far-infrared spectrum)
Exceptional performance out to 300um
Shock and vibration resistance to beyond MIL-810-G
Thermal shock and cycling from -196 to +300°C
High performance at extreme viewing angles >70° (TIS - 0.6% at 70° VIS)
Low levels of outgassing - ECC SS-Q-ST-70-02
Available as polyimide bonded for knife edges
Low levels of particulates and FOD
Applying Vantablack S-IR
Vantablack S-IR is applied using an inert gas spray process, providing very great flexibility of application on complex 3D surfaces. After spraying it requires vacuum post processing to achieve its published specification.
Vantablack S-IR can be applied to a wide range of material types. The only major requirement is that the surface or substrate material must be vacuum compatible and be able to withstand temperatures of 280°C in a vacuum environment.
The fine nanometre-sized optical cavities that make Vantablack S-IR so dark mean it cannot be used in environments open to direct contact and mechanical abrasion. It needs to be protected from accidental touching, for example behind or inside a component, or situated where contact is avoided.
Vantablack S-IR is offered as a service from Surrey NanoSystems' processing centre located near Brighton in the UK. However, the process is amenable to integration within volume manufacturing lines, and can be licensed subject to relevant approvals.
The spray-on application method required for Vantablack S-IR means that it is highly flexible, allowing it to be used to coat complex shapes and surfaces. This significantly extends the application-space for super-black coatings. Typical examples include lens assemblies, hyperspectral imaging systems, and lighter, less complex optical baffles with improved performance.
Samples of Vantablack S-IR are readily available for user-evaluation. Depending on the end application, a UK Government export license may be required. As Vantablack finds application in defence and other sectors, it has been classified by the UK Government as 'dual use'. So, some clients may require an export licence. Generic samples for customers outside of the UK require an export licence - this process normally takes around two weeks. A nominal charge for samples is made to cover the cost of export compliance.