From Light as a Source to Light as a Material: The Evolution of Planar Lighting Systems
Over the last decade we have witnessed mainstream market adoption of LED technology. LEDs have taken the market by storm and became more and more uniform in color temperature and increasingly powerful and reliable in performance and durability. Meanwhile, LED driven lighting solutions have replaced traditional lighting in many applications, both functional and decorative. A wide range of in- and outdoor applications in retail lighting, accent and display, pendants and wall-mounted fixtures now contain LED sources. The ongoing developments in LED technology have empowered the creation of new applications that did not exist before, specifically in the decorative and architectural lighting sectors.
The Next Lighting Generation: Planar Lighting
LED planar lighting solutions, also referred to as ‘flat LED lighting’, ‘LED light sheets’, ‘LED light tiles’ or ‘light paper‘ are a next generation lighting products that use LED technology to create flat illumination surfaces with a uniform light radiation. ‘Planar’ refers to the application of LEDs to create large uniform surfaces of light. Since LEDs are a single point source, creating large surfaces of uniform light has always been cost prohibitive and very in-efficient since it resulted in a significant loss of efficiency. However, new technologies are on the rise and LED planar lighting emerges as a generic product category, without compromising on optical properties, form factor or volume capabilities.
“Miniaturization is a big deal. It drives innovation in unexpected ways”.
Now, flat light sheets are no longer limited to ‘promising’ OLED technologies only, other solutions has arrived meanwhile or are just around the corner. We’ve tried to capture the main categories in order to help you stay informed about the latest developments in the field and help you decide what would be useful for your projects.
Organic Light Emitting Diodes (OLED)
OLED is a flat light emitting technology, made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted. OLEDs can be used to make displays and lighting. Because OLEDs emit light they do not require a backlight and so are thinner and more efficient than LCD displays. Most lighting companies including Philips, OSRAM, GE, Samsung, LG and UDC are working towards OLED lighting. It turns out that because OLEDs are thin and simple – they can be used to create flexible and even transparent lighting- and display solutions.
After the initial launch of OLED, recently the coming of flexible OLED was announced by LG Chem. Created entirely from plastic with no glass to break, the flexible light sheets supersede its parents in size and flexibility. This new form factor will empower the adoption of OLED and enable new applications.
Flexible Light Sheet
Cooledge Lighting introduced a flexible light sheet that provides high quality lighting while eliminating many of the constraints and challenges that existing LED systems impose. This new medium for lighting combines the mechanical, electrical and LED source together into a flexible sheet of light. The light sheet utilizes a highly dense pattern of LEDs on a thin plastic substrate, delivering on the promise of OLEDs with the reliability and performance of LEDs.
Lighting Wallpaper from Elon Technologies, is an electroluminescence based technology. A thin laminated foil emits ambient light in any pattern using the electroluminescent technology. It is manufactured on high precision screen print from polymer layers laminated together. Lighting Wallpaper is, as its name suggests, a brilliant solution to cover walls and other interior design objects with ultra-thin sheets of light. Since it is created with a printing process, full-color graphical expressions can easily be added.
LED Light Tile
A potential OLED killer – lighting you can roll up like a newspaper. The thin, flexible LED Light Tile from Design LED has built-in optics giving it uniformity and a consistent beam angle. At the core of Design LED’s technology is the integration of low profile LEDs, clear optical resins and optical films into a high efficiency light tile.
In its current state, ‘Lightpaper’ by Rohinni is manufactured by mixing ink and tiny LEDs together and 3D-printing them out on a conductive layer. That object is then sandwiched between two other layers and sealed. The tiny diodes are about the size of a red blood cell, and randomly dispersed on the material. When current runs through the diodes, they light up.
LunaLEC Liquid Light
In the scientific community, the LunaLEC Liquid Light technology is known as the Light-Emitting Electrochemical Cell (LEC). From a distance and a layman’s perspective, this technology is very similar to the Organic Light-Emitting Diode (OLED), as both technologies use a flat planar lighting structure in which the light-emitting organic layer is sandwiched between two conductive electrodes. LunaLEC Liquid Light comes with both glass and plastic embedded liquids.
Embedded Lighting – What’s more…
There are other large surface lighting solutions that enable to apply light in a different way, just to mention a few: the impressive Coelux Skylight and some Philips innovations that cover a certain area of the room as a whole: Philips One Space for ceiling spaces, Luminous Patterns for decorative walls and Luminous Carpets to light up your floor or embed functional or directional elements.
Embedded Lighting: Light as a Material
Today’s designers want to treat architectural lighting more like an embedded material than as a series of discrete objects. Minimalistic design is hot. There is tremendous potential for this fusion of light and material, but custom integration of embedded lighting traditionally have been difficult to specify, risky to budget, and costly to install, limiting the broader adoption of such “embedded” lighting.
The coming of planar light sources now makes it easier than ever before to fuse light into building materials, opening up a creative new area of exploration for architects and interior designers.
Freedom of Design and Choice
There is no ‘one-fits-all’ solution and we don’t want to prefer or recommend one above the others. Every application requires a different approach and any of the planar led lighting products as mentioned above could fit. It’s above all the choice of the lighting architect or interior designer that defines the best fitting product for the application. Aesthetics, overall ambiance, form factor and cost are key in deciding what solution works best. Above all, the end-user will decide which of the above mentioned products will finally break through!