Multilayer polymer film reflects chosen wavelength bands with a metallic luster
Film can be used to hide IR sensors on metallic surfaces.
|An inexpensive many-layered polymer film that transmits near-IR light appears metallic (at left, although hard to see in the photo). Even when the film covers the IR sensor of an electric appliance, an IR remote control can be used. A dichroic version of the film (right) has other uses, such as anticounterfeiting. (Images: Tech-On!)|
As noted in Tech-On!, Toray Industries (Tokyo, Japan) has unveiled new products in its "Picasus" series of films that realize a metallic luster without using a metal. The film does this using several hundreds or thousands of layers of different polymers that are alternately stacked.
In the new films, Toray made improvements to its polymer lamination technique and enabled the custom-controlled reflection of light over the visible to near-IR light band.
With the improved lamination technique, Toray reduced individual layer thickness tolerances from several tens of nanometers to several nanometers; as a result, the wavelength band within which reflectance changes from high to low or the reverse was narrowed by about 90%. The company developed three new products: near-IR light transmitting metallic luster, dichroic, and blue light cutting films.
"Metal" that transmits IR
The near-IR light transmitting metallic-luster film looks like metal but transmits near-IR light with a wavelength close to 950 nm. When used to cover IR sensors on TVs, appliances, faucets, and so on, it makes the entire product look metallic.
The dichroic film changes its color tone in accordance with view angle. Toray expects that it will be used for preventing labels from being counterfeited, as well as for ornamental use.
The blue-light-cutting film reflects only blue light, which is believed to cause eye strain and lack of sleep. It is used to block blue light emitted from a PC display, or smartphone screen.
The new films are already available for sale.