How Does Switchable Glass Really Work?

How Does Switchable Glass Really Work?
September 28, 2021 admin

Switchable glass has become increasingly popular over the last decade. The clever properties of switchable glass technology are reflected in its multiple names; switchable glass, smart glass and also privacy glass. At Polytron, we specialise in Polymer Dispersed Liquid Crystal (PDLC) glass. But there is a broad range of switchable glass in existence, used for multiple different applications; from residential and commercial (Polytron’s forte) and even glasses and eyewear. Read on to discover the different types of switchable glass out there, and how they all work.

Switchable Glass For Homes, Buildings And More

Both stylish and functional, switchable glass that is made for homes and buildings never fails to impress. The science behind this impressive glass is also pretty incredible. This type of switchable glass is made with PDLC film. But what is PDLC? PDLC is a film that contains liquid crystal droplets, the size of a micron. This film is critical to making the glass switchable. The PDLC is sandwiched between two layers of glass laminate, along with adhesive interlayers. These materials are then cooked in a pressure oven to become one unified sheet of switchable glass.

The liquid crystal droplets of the PDLC film have light scattering properties. This allows the glass to switch from opaque to clear, and vice versa. The matrix of droplets within the glass are coated in Tin Oxide. This allows them to conduct electricity.

Electrical wires are placed on at least two corners of each piece of switchable glass. This allows the user to inject an electrical current via a switch.

When no electrical current is present (when the switch is ‘OFF’) the glass remains at a completely opaque state. This is because the crystal molecules are randomly oriented in this state, thus scattering the light.

When a user flicks the switch and turns the smart glass ‘ON’, the electric current will flow into the crystal molecules. This forces them to line up, allowing light to pass through, making the glass instantly transparent.

As the glass is opaque when the switch is off, the glass will naturally revert to opaque in the case of a power outage.

Switchable Glass For Climate Control

Far less common than PDLC glass, thermochromic glass tends to be used more for building construction, rather than residential or commercial building applications.

Thermochromic glass is activated by heat. As the sun continues to heat the pane, the window glass tints and darkens. This allows less light to permeate through. Multiple types of thermochromic materials are available, with each type coming with different properties. That said, the most common type tends to be Vanadium dioxide.

Thermochromic glass is exceptional at blocking heat on warmer days, and retaining heat on cold days. It is therefore excellent at climate control. Hence, it tends to be used more in building construction.

Installing Switchable Glass?

The advances in glass technology have offered significant benefits across countless sectors. With Polyvision switchable glass, homes, offices, hotels, hospitals, marine vessels and more all have access to safe, reliable privacy glass that comes with countless functional benefits. If you would like to enquire about Polytron’s Polyvision switchable glass, be sure to contact our helpful team today.