SCHOTT developers have further improved the nanoimprinting process. Now it can even be used to produce hologramson glass surfaces.
Photo: SCHOTT/C. Costard
Guiding Light with Precision
SCHOTT developers are creating nanostructures on glass surfaces and transforming nanoimprint techno-logy into a platform for creating innovative products and applications.
Under the lens of an electron microscope, they form a landscape of mysterious identical sculptures: periodically arranged silicon crystals on a glass surface. Engineers can specify their exact size, shape, and spacing down to the micrometer and nanometer. To allow even greater precision, SCHOTT developers have refined a process for nanostructuring surfaces that is one of today’s most important emerging technologies: nanoimprint lithography.
Using this nanoimprint technology in combination with special coating materials and processes, developers can create complex functional surface structures. These structures are so small and sophisticated that they can direct, reflect, absorb, or manipulate incident light. This technology can also be used to generate surfaces with specific haptics or decorative flair.
The production process includes a curing step with ultraviolet light. Photo: SCHOTT/C. Costard
SCHOTT has also applied the principles of chemical nanotechnology to develop a special sol-gel based nanoimprint coating. Applied to a glass substrate, this coating accommodates a wide variety of features, such as a customized refractive index for optical applications.
A stamp is produced to manufacture an optical interference screen for diffracting light (left). SCHOTT also employs this technique to produce a realistic brushed stainless steel look on glass (right). Photo: SCHOTT/C. Costard
”This technology platform opens the doors to a wide variety of possible applications. We have secured broad patent protection for our materials and processes that will cover numerous applications,” comments Dr. Matthias Bockmeyer, SCHOTT Senior Manager on Material Development. Other possible applications include architectural glass with special anti-reflective surfaces, holograms for product trademark protection, and optical nanostructures for light emission on OLEDs (organic light-emitting diodes). Diffusion filters to distribute light more evenly on video screens are another option. Also, optical ”light-trapping” concepts for more efficient absorption of light by the nanostructured substrate could be an interesting application for thin-film solar technology.
At SCHOTT, developers are already working on a decorative application for household appliances: the creation of a realistic brushed stainless steel look on glass. This allows the advantages of glass, such as easy cleaning and scratch resistance, to be combined with the elegant, stylish look of metal. Furthermore, nanoimprint technology allows many different colors and shapes to be used on glass surfaces.
The periodically arranged, wavelength-ordered crystalline silicon structures mentioned at the beginning of this article, which are being developed in a joint project with the Helmholtz Center in Berlin, could be an important future field of endeavor for SCHOTT. One of the primary project goals is the low-cost production of photonic crystals for the controlled manipulation of light propagation in a material and/or how light interacts with it. This should significantly boost (optical) data processing power – a prerequisite for the optical supercomputer of the future. <|
Research and Technology Development