Switchable glass is a type of glazing which utilises certain technologies to alter its light transmission properties at the flick of a switch. In most cases, the glass changes from translucent to transparent as wavelengths of light are hindered or allowed through the glass. For example, frosted glass can be made completely transparent, thereby permitting the operator to adjust levels of privacy.
A variety of technologies are used in switchable glass/smart-glass devices including electro-chromic, thermo-chromic and suspended particle layers. For electro-chromic versions, a low voltage of electricity darkens the coating (usually ceramic) as lithium ions and electrons are transferred from one electro-chromic layer to another. When the polarity is reversed, the ions and electrons return to their original layer which causes the glass to revert to its transparent state. All this is controlled through a voltage supply which is usually lower than 5v.
Switchable glass is becoming more common in contemporary building designs and can be used effectively in windows, skylights and doors. It’s also possible to minimise glare while maximising available daylight as well as protecting against harmful UV rays – in fact, it’s been found that switchable glass can completely eliminate UV rays. All of its functions can often be instigated with smart-phone or tablet devices.
In addition to convenience, smart-glass opens up all kinds of avenues for architects, especially with regards to energy efficiency and climate control. It certainly doesn’t stop the need for curtains and blinds, but it does act as a good accompaniment to them. So it’s for multiple reasons that the product has started to become common in large offices and big-businesses.
Although glass that changes tint is a relatively straightforward concept, getting it to work properly has presented significant engineering challenges, which is why it’s taken around twenty years to perfect. However, new strides in the area have been heralded as revolutionary by those in the industry. As it stands, the product is being used predominantly in the commercial and healthcare industries, although some luxury home-owners have also started to use it. In the US, for example, smart-glass is being used more and more in residential properties.
Given the technology used in its functionality, it is somewhat unsurprising to note how expensive smart-glass actually is. Due to relatively short existence as a viable commercial product, there are some questions about its durability and reliability. Moreover, many current versions take several minutes to transfer between clear and opaque. So it’s evident that further refinement is required if it’s going to succeed in the mass-market.
Nevertheless, the future is certainly bright. Electro-chromic technology and the like is in a constant state of evolution, so it’s reasonable to assume that engineers will find a way of improving on the current process required to make this special glass work, thereby reducing the costs of production and improving its usability. It’s therefore likely that smart-glass is here to stay.