Living room lamps, mobile phone screens and LCD televisons: nowadays, almost all light-emitting devices use LED technology. Because the light from the LED is blue, the wavelength of the lamp must be optically modified to other colours. This creates what the user perceives as “warm” light or the colours on the screen of a television. To do this, colour filters made of metals classified as “rare earth elements” are used. These metals are difficult to recycle and are extremely expensive due to their rarity. A group of researchers from Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) is developing a method to replace these inorganic colour filters with layers of fluorescent proteins.
On the Way to an Organic Screen
Dr. Rubén Costa’s research group has been researching the possibility of replacing inorganic materials in LED lights with fluorescent proteins for a long time. The biggest problem they faced is that proteins rapidly denaturate outside of their aqueous buffer solution, and thus become unstable. The researchers were now able to solve this problem by mixing a highly concentrated potrein solution with a polymer to form a gel. The gel is vacuum dried and becomes a rubbery material which can be used for the layers of LEDs, while protectiong proteins from external influences.
“The fluorescent proteins […] are environmentally friendly and inexpensive to manufacture. In addition, the proteins allow the colour setting – either coloured or white – to be controlled easily,” explains Dr. Rubén Costa. “This is a pioneering method for future generations of LEDs.”
The proteins are not just well suited for simple LED lamps. The FAU researchers found that the protein-polymer mix can be molded into the microstructure required for displays using 3D printing. This is essential because on displays, each LED light must project a different color to create a colorful, changing picture. Since the protein layer is very soft, it could also be used in flexible devices.
The protein LEDs, named „OLEDs“ (organic LEDs), could thus soon be a cost-effective and organic alternative to the color filters made of rare earth elements. We can only hope that this innovation will successfully make it from the laboratory to the mass market.
This article is a translation from German of Laura Wagener’s article on our German page.