In recent years, the market for light-control glass has expanded due to the increasing demands for energy efficiency and heat and light control, automated shading, privacy, and design and engineering innovation.

Smart Glass or Switchable Glass is a product of cutting-edge technology that allows users to block either all light or just some by simply turning a knob or pressing a button. This type of light control could potentially save tremendously on heating, cooling and lighting costs.

Smart Glass technology basically means controlling the transmission of light through glass by using electrical power. By applying a variable voltage to the glass, the amount of transmitted light can be controlled. Switching speed and the consistency of a tint change are among the most important attributes to potential users of smart glass technology.

The processing technique of Smart Glass is to combine Smart Film with glass through a certain process to ensure reliable use.
Why it is so called?

When a product is called “smart”, it simply means it is programmed with an auto-intelligence capable of operating a single task. And the same goes for smart glass: instead of relying on glass treatments to block the light, these specially designed, energy-efficient glass panes automatically control the sun^s solar penetration.

How does Smart Glass Work?

Switchable glass panes dim and brighten at will. When you want sun to shine through your windows, simply flip a switch to turn off the tint. You want to open a room, another flip and the windows will blur, become opaque, or slowly darken. Though they all perform the same task, there are several types of smart glass available. One of the original forms is photo chromatic technology which doesn^t require manual operation. Similar to sunglasses, these panes immediately tint when the sun hits, which is efficient since they don^t call for any electricity or hands-on direction.

Smart glass technologies include electrochromic devices, suspended particle devices and liquid crystal devices

1. Suspended Particle Devices

Suspended Particle Devices are constructed with two panes of glass separated by a conductive film with suspended, light absorbing, microscopic particles. These microscopic particles within the Suspended Particle Devices (SPD) absorb light, thus preventing it from passing through the film. When the electrical current is added to the film, the particles align themselves to allow light through the glass. The switchable system consists of a non-toxic film between two panes of glass - the higher the current, the more arranged the particles are, and consequently more light is allowed through the glass or plastic.

When the current is switched off, the particles are scattered, inhibiting light penetration. SPD films, which operate off an AC voltage or battery power, consume a very minute power of 0.05 watts/square feet maximum. Users can instantly and precisely control the transparency of the window by manually adjusting a dial connected to a rheostat or automatically setting the opaqueness by programming a photocell.

Smart glass using SPD technology takes several seconds to change from dark to clear, and tint changes are consistent regardless of panel size.

2. Liquid Crystals

Working similarly to SPD technology, these products are black and white: turn it on, they line up to permit light; turn it off, you^re in the dark again. Liquid crystal smart glass changes its properties the most quickly of all—from translucent to transparent in milliseconds—and tint changes occur consistently regardless of panel size. Liquid crystal smart glass does not offer a shading benefit, but the view through the glass is blocked when in its translucent state. As such, this product is primarily used for interior needs (e.g., bathrooms) where privacy is required.

3. Electrochromic Glass

Electrochromic Glasses work in the opposite manner. When a current is supplied, they darken and when electricity is withheld they become clear. Another unique aspect of these is that they aren^t so black and white. Instead they are able to create varying levels of light penetration, allowing total management of the sun^s power. Sometimes it takes several minutes to change shades and typically electrochromic glass works from the outside to the center, but it also doesn^t require a constant stream of electricity. Once the initial tint is achieved, no more power is needed.

The switching speed of electrochromic glass is slowest overall and varies depending upon the size of the panel (larger panels typically take many minutes to switch). The consistency of tint changes also varies, with larger panels sometimes exhibiting tint changes that begin at the glazing’s outer edges and then move inward (known as the “iris effect”).

Applications

Smart glass can be applicable in the following areas:

Applications of smart glass include building windows, doors and skylights; automobile, boat and aircraft windows; appliance windows, computer screens and cell phone screens. Its use in home and residential windows can all but eliminate the need for blinds or shades, and it fits in with the "green movement" by helping with interior heating and cooling.

Advantages

Dynamic glazing technologies
 
Smart glass represents a category of glazing materials that visibly change their properties in response to a stimulus. In doing so, smart glazing in windows, doors, skylights and partitions offer varying levels of dynamic control of light, glare and heat.

1. Passive smart glass

Passive smart glass operates with no electrical interface and is typically found in small-format applications. Self-dimming eyewear that reacts to the presence of ultraviolet light is an example.

2. Active smart glass

The most exciting development in the architectural arena is active smart glass products, including those using liquid crystal, suspended particle device or electrochromic technology. Active smart glass requires an electrical stimulus to change its light-control properties, and power consumption levels are very low. The operating performance of active smart glass depends on the type being considered.

High-performing smart glass products provide unprecedented levels of advanced light-control while also making instant and dramatic design statements. Sleek and innovative, smart glass is tremendously empowering. Just as significant is its array of functional benefits (tunable shading, privacy, glare reduction and remarkable energy efficiency) that support the sustainable design goals of resource conservation and the well-being of building occupants.