ActiveGlass employs a unique patented technology which acts like a finely tuned filter to control light and heat transmission. It is completely different from all other known smart glass systems – most of which rely on electricity to manage the effect.
ActiveGlass does not use electricity – although this may be required for remote operation, where a small motor is used to actuate the mechanism.
The new technology patented by Active Glass brings with it a compelling feature, in addition to its other performance benefits – cost.
The nature of the technology allows us to use quite different manufacturing processes – these are inherently much lower cost methods than those needed to make other smart glass systems. ActiveGlass units can be produced for less than a quarter of any other smart glass technology. We anticipate this will have a major impact on the take up of smart glass in commercial and residential buildings.
The principle of operation is described in a number of patents, all owned by Active Glass Technologies PLC – and further patents relating to this technology are under way.
The following is a very simplified explanation, but we hope this gives you a rough idea of ‘how it works’.
Imagine, some fine black lines printed across a sheet of glass, all exactly parallel to each other, with gaps between lines the same as the line widths. Each line is so thin, that when you stand a couple of metres away from the glass, you cannot see the lines (it’s below the resolving limit of the eye). If you look at the whole pane of glass very carefully, you may just see that it appears very slightly darker than a similar piece of clear glass with nothing printed on it.
Now, imagine a second sheet of glass – exactly the same as the first – placed immediately behind, and aligned precisely so that the printed lines are all in the same relative position. When you look through the two panes of glass, you see the same thing as when you observed just the first pane – because the lines are all superimposed along your line of sight. You see a very slight shading or tint looking through the glass – actually not noticeable without another plain piece of glass to compare with. Because of the eye’s logarithmic response to light intensity, halving the light level for example is perceived as only a slight change in brightness.
Finally, let’s actuate the glass: shift one pane by just the width of a line, so that it covers the gap between lines on the other pane. Now when you look through the combination, the entire window is obscured by our special printed material and all light is blocked. You can adjust the amount of light filtration by moving one pane by less than a line width – to get anything from completely ‘clear’ to fully opaque.
The above is a gross simplification. In practice we use specialist materials, novel print technology, and clever engineering to get effective and robust performance. We also use multiple layers of material with different line widths to optimise transmission and performance.