General Motors has received a patent for a fascinating self-cleaning technology that could eliminate the annoyance of smudgy fingerprints all over touchscreens. It's a photocatalytic system, triggered by ultraviolet LEDs built into the RGB matrix.
The system sounds relatively simple, but requires some fairly fundamental changes to the pixel array behind the screen. Where most screens use red, green and blue LEDs, set at different intensities, to create their full color palette, GM's design would add a fourth pixel throughout the matrix, specifically tuned to the invisible ultraviolet wavelength. On the surface of the screen, there'll be a fully transparent layer of some kind of metal-oxide-based photocatalyst – probably titanium dioxide, which we've seen used before on
self-cleaning solar panels and a range of other applications.
When
exposed to UV light, titanium dioxide goes from hydrophobic to super-hydrophilic, and begins attracting moisture out of the air. This creates a thin layer of water on the surface – and it starts oxidizing that water to electrochemically generate free radical molecules, which attack the cell walls, cytoplasm and DNA of bacteria, fungi and other biological organisms. Effectively, it kills most organic material on the surface, breaking down oil residues and other debris as well. So it slowly cleans and sterilizes the screen, and when the UV light is taken away, the surface goes back to being water-resistant, allowing the moisture to bead up and roll off the surface. All of which is well and good for self-cleaning windows and solar panels that are exposed to sunlight all day, but it won't do much for the touchscreen in a car, or a laptop or tablet that's typically kept inside.
newatlas.com
