Researchers are creating vivid, permanent colors by carving nanoscopic 'voids' into silicon instead of using pigments or ink.
March 31, 2026
Original Paper
Single-Step Grayscale Lithography of Multi-Depth Mie Void Metasurfaces
arXiv · 2603.27574
The Takeaway
This 'paint-free' printing uses microscopic holes of different depths to trap and reflect specific wavelengths of light. Because the color comes from the physical shape of the holes rather than chemical dyes, it allows for high-precision, indestructible images that will never fade or peel.
From the abstract
The height of dielectric metasurfaces is largely considered a constant in the fabrication process due to the top-down fabrication approach, resulting in a binary structure. Yet, for the recently introduced Mie voids metasurfaces, controlling the thickness of the voids locally is crucial for achieving significant spectral tuning. In this work we demonstrate Mie voids metasurfaces with local precise depth control using electron beam grayscale lithography. We underexpose PMMA with varying doses, wh