𝐍𝐚𝐭𝐮𝐫𝐞 𝐈𝐧𝐬𝐩𝐢𝐫𝐞𝐬 𝐖𝐚𝐭𝐞𝐫-𝐑𝐞𝐩𝐞𝐥𝐥𝐢𝐧𝐠 𝐀𝐥𝐭𝐞𝐫𝐧𝐚𝐭𝐢𝐯𝐞 𝐭𝐨 𝐏𝐅𝐀𝐒

Researchers at Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS) have developed a foam-based technology that mimics nature’s ability to make brilliant white materials and control water repellency without (TiO₂) pigments or fluorinated coatings (PFAS). 

Look closely at Hokusai's The Great Wave off Kanagawa, one of Japan's most iconic masterpieces. The brilliant white of the waves, the snow on Mount Fuji and the clouds above contain no white pigment. Instead, their whiteness comes from the way light scatters off the unprinted fibers of the washi paper itself.

This optical phenomenon known as structural whiteness—is the same mechanism that makes sea spray, snow, and clouds appear bright white in nature.

This natural phenomenon inspired an international research team—led by Professor Easan Sivaniah of Kyoto University, alongside collaborators from Tokyo Metropolitan University and Donghua University to develop a new foam-based materials platform.

Today, white packaging, films and coatings rely heavily on titanium dioxide to provide brightness and opacity in creating white materials, but safety concerns recently led the European Union to ban its use as a food additive.

To address these challenges, the team developed a technology that generates whiteness and controls water repellency through precisely engineered porous structures that reproduce the light-scattering behavior of natural foams, drawing inspiration from natural surfaces such as leaves and flower petals.

The fabrication process is remarkably simple. It uses light followed by treatment with a mild solvent. Light first breaks the polymer into smaller molecular fragments. These fragments interact with the solvent, causing the material to swell and form an open, porous structure. Through this single process, the material achieves two distinct functions. Internally, the porous structure scatters light to create intense whiteness without added pigments. On the surface, the foam transforms into an extremely rough structure with strong water-repellent properties, similar to those found on a lotus leaf.

The research team named this technology Deep Foam Photolithography (DFP).

Working with textile researchers at Donghua University, one of China’s leading institutions for textile science and engineering, the team demonstrated that the process can be applied not only to printable polymer films but also to fabrics. I

The result is a new printable materials platform, capable of ultrahigh resolution (20,000 DPI), that combines structural whiteness with water-management functionality—without titanium dioxide and without PFAS.

Reference: Qin D, Liu X, Kuang B, et al. Foaming photopolymers as a high-resolution biomimetic printing platform. Nature. 2026. doi:10.1038/s41586-026-10968-9

source : Technology Networks