Gizmos & Gadgets: Tunable Windows

June 12, 2015 – University of Cincinnati, Hewlett-Packard and EMD/Merck Research Labs have combined their research to create a smart tunable window. What does that mean?

The window uses adaptive optics to adjust the opacity of the window without limiting the amount of light that can pass through it. It can go “milky” for privacy, or you can change the colour of the light from “cool blue” to “warm yellow.” And the windows serve to provide complete privacy. No blinds or other window coverings required. The full range of colours are seen in the image below. Note the opacity still allows you to see the hand behind the glass.

The research behind the invention is reported in an article entitled, Electrokinetic pixels with biprimary inks for color displays and color-temperature-tunable smart windows, in the June issue of the journal, Applied Optics.

The material used is adaptable to existing windows and can be rolled-on as a coating. It is a multi-layer honeycomb of electrodes with embedded electrophoretic ink that is tunable to four different states. Even at its darkest setting it will let in 90% of the light while giving those in a room full privacy. It does this by turning the window milky. The schematic below illustrates the mechanism behind this unique capability.

The best thing about these windows, they are relatively inexpensive to manufacture, as is the coating that can be used to retrofit existing windows. I expect University of Cincinnati’s industrial partners to bring the technology to market in the near future.