Smart glass, or switchable glass, is glass that uses advanced technologies to block light and insulate. The glass’s light transmission properties can be affected by light, heat or electricity. Mostly, this means the glass changes from translucent to transparent, blocking some, all or certain wavelengths of light. This technology can be applied to control light, heat, and privacy in homes, businesses and institutions such as hospitals. They provide cleaner environments and offer higher and differentiated levels of control than manual solutions such as blinds, curtains, shades and doors.
- Polymer-dispersed liquid crystals
Electrochromic Glass: As the name indicates, these devices change glass properties in response to electricity and therefore lend control over the amount of light and heat transmitted. Once the desired level of opacity is set, no further electricity is needed to maintain it. This change occurs slowly, but settings can be adjusted to user preference. Windows on buildings, rearview mirrors, and museum display cases are examples of how electrochromic smart glass can be used. One drawback to the technology is that it may affect the durability of the glass.
Photochromic Window Tint: Similar to electrochromic glass, the transference of light through photochromic glass is affected by an outside source, only this time it’s UV radiation (generally, but it can be affected by any light of sufficient intensity). However, unlike electrochromic glass, the transparency changes when the applied light source changes. This technology is most commonly seen in optical lenses that block the sun when outdoors but remain clear otherwise.
Thermochromic Glass: As you might guess, thermochromic glass translucence changes when heat is applied. This change happens when the external temperature rises above the transition temperature and the thermochromic filter on the glass activates, transitioning the tint on the window in just minutes. This technology blocks light, heat and glare while retaining clear views through the glass.
Suspended-Particle Glass: For opacity, the nanoparticles on this type of smart glass are randomly organized to block and absorb light. When electricity is applied, the suspended particles align to allow light to pass through. The amount of light allowed to pass depends on the variance of voltage, giving full control to the user. With electrically switchable smart glass, the voltage can be controlled through photosensors, motion detectors, apps, integration with computer systems, or knobs and switches.
Micro-Blind Smart Glass: With this type of smart glass, micro blinds – thin, rolled metal blinds – on the glass can be controlled with electricity. When there is no voltage, the blinds are rolled and light can pass through. When electricity is applied, an electric field forms between the glass and the blinds that makes the blinds unroll and flatten out to block the light. This type of smart glass provides a level of privacy too and can be adjusted just like regular blinds to control light and privacy settings.
Polymer-Dispersed Liquid-Crystal Glass: Dissolved liquid crystals on the polymer or glass in this technology harden and form droplets throughout the polymer or glass sheet, as the crystals are not compatible with the other materials. These droplets scatter the light and make the glass appear milky. When electricity is applied, the liquid crystals align and allow light to pass through, similar to suspended-particle glass. This type of smart glass is typically used in bathrooms, conference rooms, and ICU areas of hospitals for privacy control.
Currently, these technologies can be quite expensive, but for some business and homeowners, they may be a good solution to light and insulation controls.