Anti-Fingerprint Photocatalytic Nanostructure for Transparent Surfaces

Technology #16220

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Inventors
Professor Robert Cohen
Department of Chemical Engineering, MIT
External Link (cohengroup.mit.edu)
Professor Michael Rubner
Department of Materials Science and Engineering, MIT
External Link (web.mit.edu)
Professor Gareth McKinley
Department of Mechanical Engineering, MIT
External Link (meche.mit.edu)
Professor George Barbastathis
Department of Mechanical Engineering, MIT
External Link (meche.mit.edu)
Johnny Choi
Department of Mechanical Engineering, MIT
Kenneth Park
Department of Mechanical Engineering, MIT
Hyomin Lee
Department of Chemical Engineering, MIT
Managed By
Jim Freedman
MIT Technology Licensing Officer - Chemicals, Instruments, Consumer Products
Patent Protection

Anti-fingerprint photocatalytic nanostructure for transparent surfaces

US Patent Pending 2014-0336039

Applications

This technology can be used to produce flexible glass/polymer-based surfaces for a wide range of commercial products including: touch screens, touch pads, electronic displays, glasses, goggles, windows, windshields, optical device lenses, photovoltaic cells and light bulbs (including LEDs).

Problem Addressed 

The micrometric pattern of fingerprint films usually scatters light and results in blurry images behind optically transparent and distortion free smooth surfaces such as windows, glasses, touch screens and electronic displays. Fingerprint-resistant coatings can be applied to avoid unwanted oily fingerprint films on these transparent surfaces.

Technology

The inventors have developed a method that exploits the photocatalytic oxidation of titanium dioxide nanoparticles as a way to chemically degrade deposited fingerprint oils. This technology consists of a nanotextured surface comprised of multilayers of titanium dioxide and silicon dioxide nanoparticles deposited on transparent substrate. The outermost layer of the coating is composed of pure TiO2 nanoparticples, maximizing both photocatalytic oxidation, to remove oils, as well as the optical transmission of the transparent coated surfaces. The thin layers between the outermost layer and the substrate can be composed of SiO2, TiO2, glass, polymer, metal, etc. to provide additional functionalities such as anti-reflectivity, anti-fogging or anti-scratch properties.

A layer-by-layer assembly technique is used to enable uniform coating thickness of each layer to ensure good optical property. Oppositely-charged polymeric and nanoparticle solutions are used to ensure a conformal coating that reduces light scattering and haze. This coating method enables extremely precise control of film thickness and uniformity even on curved surfaces, compared to other typical coating methods such as dip-coating, spray-coating and solvent casting.

Advantages

  • Coating method provides anti-fingerprint, anti-reflection, anti-fogging, anti-scratch and anti-bacterial properties
  • TiO­2 coating maximizes photocatalytic effect and optical transmission to achieve rapid removal of fingerprint film
  • Coating method can be applied to large area curved substrates with uniform thickness
  • Coating has high mechanical durability to reduce cracks and defects on flexible substrates