Turning up the shade

Consider the following scenario. The sun’s so bright you’ve got to wear shades, but as soon as you set foot in your favourite public house the poor lighting causes you to stagger about and bump into tables as if you’ve been in the hostelry all day.

An effective solution to this problem would be to remove your glasses and put them in your pocket. However, why take off your cool shades when you can simply turn them down?

As well as adjustable sunglasses; windows, sunroofs, mirrors and flat panel displays are all areas which could benefit from Research Frontiers’ SPD (suspended particle devices) technology.

Also referred to as `light valves’, the devices use either a liquid suspension or a film within which light-absorbing microscopic particles are dispersed. The suspension or film is enclosed between two glass or plastic plates coated with a transparent conductive material. When an electrical voltage is applied to the suspension via the coatings, the particles are forced to align. This allows a range of transparency where light transmission can be rapidly varied to any degree desired depending upon the voltage applied.

SPD film can be laminated to a glass or plastic surface where the amount of light transmitted through it can be either adjusted manually by the user, or automatically via a photocell.

A smart window, for example, would enable users to precisely control the amount of light passing through the window, providing relief from glare or heat without blocking view.

The roots of this technology can be traced to Polaroid’s founder, Dr. Edwin Land, who invented the first `light valve’ in 1934, and it is Polaroid that has now acquired a world-wide non-exclusive license to manufacture and sell SPD films to Research Frontiers’ current and future SPD end-product licensees.

Copyright: Centaur Communications Ltd. and licensors