A domestic research team has developed a new technology that can produce 'metasurfaces,' the key to next-generation display technology, more efficiently.
Professor Noh Jun-seok of Pohang University of Science and Technology POSTECH’s mechanical engineering, chemical engineering, electrical engineering, and converged graduate schools noted on the 17th that his research team developed a technology that complements the drawbacks of existing metasurface production methods. The research results were published on the inside front cover of the international academic journal 'Advanced Science' on the 13th (local time).
Metasurfaces are technologies that freely control light using structures at a size of approximately 1/100,000 the thickness of a human hair, at the scale of nanometers (10 billionths of a meter). Utilizing this technology can produce clearer and more vivid colors than existing displays and can also be applied to advanced image technologies such as holograms.
Recently, the 'Particle-Enhanced Resin Imprinting (PER-NIL)' process has been gaining attention as a method for mass-producing metasurfaces at low cost. This method involves using a special liquid (resin) that contains nanoparticles that greatly refract light to create patterns like stamping. However, the high-refractive thin film that remains on the substrate after the pattern is formed scatters light, reducing the efficiency of the metasurface.
The research team solved the limits of the particle-enhanced resin imprinting process using a simple method involving tape. After experimenting with various types of tape, they found the optimal conditions to effectively remove only the thin film while maintaining the nanostructures.
In particular, for 'structural color metasurfaces' that display colors due to the interference of light from the nanostructure, this technology can achieve even clearer colors. Previously, the thin film caused unnecessary reactions with light, resulting in dull colors, but using the newly developed technology allows for complete removal of the thin film, thus achieving much clearer colors. Applying this method to metasurface technologies that create three-dimensional images, like holograms, can solve issues related to light scattering and reduced transmittance due to the thin film, resulting in much clearer images and videos.
The greatest advantage of this technology is that it simplifies the process. Previously, complex chemical treatments were necessary to remove the thin film, but the research team’s method can achieve the same effect simply by sticking and pulling off tape. This method is also suitable for mass production and can be applied to continuous product manufacturing using the 'Roll-to-Roll' method.
Professor Noh Jun-seok said, 'This research is the first case of reproducing a high-refractive metasurface without a thin film,' adding that, 'It is expected that metasurface technology will become closer to real life through this.'
References
Advanced Science(2025), DOI: https://doi.org/10.1002/advs.202409371