Automotive manufacturers have started to offer tintable smart glass to some vehicle models. In this blog we look how using flexible liquid crystal cells in smart windows can bring benefits to vehicle design, environmental impact, and the customer experience.
With winter bringing shorter days, the sun is now noticeably lower during my daily commute to and from the FlexEnable office. It is not a long journey by any means, but at the moment I do seem to spend a fair amount of time trying to avoid the sun’s glare. By a quirk of design, the sun shade below my sunroof is not opaque and the light seems to hit it at just the wrong angle every morning and I have to adjust my position more than once to ensure that the sun is not in my eyes – not ideal when travelling along busy roads – and I find myself wishing for a simpler solution.
Tintable Smart Glass
In the past few years, automotive manufacturers have started to offer tintable glass as an option, providing a controllable way to adjust the amount of light and heat let in to the vehicle using glass liquid crystal (LC) technology. However, these have almost exclusively been used in smaller areas where the glass requires less curvature, or curves along a single axis, such as sunroofs – the manufacturing and forming process requires high temperatures, and more complex curvature can be difficult to achieve.
Vehicle design – efficiency is key
Vehicle design is trending towards flowing lines with curved surfaces and lightweight glass for practical reasons, as well as aesthetics. The Drag Coefficient, an aerodynamic measurement of how well a vehicle travels through the surrounding air, is now an important spec in the list for manufacturers and for customers. A low drag coefficient can potentially mean a longer range and higher efficiency for electric cars and less fuel burned for combustion engines – a feature important to todays’ customers looking to make a more environmentally conscious purchase.
Flexible Liquid Crystal cells: conformable, fast, energy efficient
There is therefore a clear need for automotive smart glass that can both conform to today’s vehicle design requirements and offer LC technology for smart dimming. FlexEnable’s flexible organic transistors and LC cells, manufactured on plastic at a far lower temperature than glass, are the solution.
By using plastic substrates, the resultant LC film can easily be curved in two directions (biaxially), a requirement for the modern, efficiency-focused design of automotive glass surfaces. It can therefore be conformed to the curvature of any window, while adding virtually no extra weight at less than 100 microns thick.
This enables glass that is lighter, colour neutral, and can be switched at video rate to clear, tinted or anything in between. It can also be segmented, meaning that sections of the glass could be tinted/dimmed at different levels in different areas – for example, a darker strip across the top of a window to stop sun glare.
For automotive manufacturers, FlexEnable’s technology provides a low-temperature process that meets cost requirements with less environmental impact, and enables a new set of features and design possibilities for vehicles across a range. For customers, it brings features such as dimming to stop glare, for privacy, or to prevent the vehicle interior from heating up in strong sunlight and protecting valuable items inside.
In the case of my commute, a smart roof with automatic or controlled dimming that can switch quickly and prevent sunlight glare and manage heat effectively would definitely be a less cumbersome solution, and would certainly cause less wear on the sunshade (and my patience!).