Researchers at the University of Konstanz have introduced a novel, contact-free technique for removing liquids from delicate microstructures. This innovative method employs vapor condensation to create surface currents that efficiently transport liquid droplets away from microscopic surfaces. The findings, published on January 13, 2026, in the journal Proceedings of the National Academy of Sciences, hold significant implications for industries relying on microchip technology and other sensitive components.
Microchips, essential in devices such as smartphones, undergo manufacturing processes that expose their surfaces to various liquids. These residues must be meticulously eliminated to ensure optimal performance. The research team, led by physicist Stefan Karpitschka, has developed a technique that leverages the natural surface tension of liquids to facilitate this removal process.
Understanding the Science Behind the Method
Surface tension is a fundamental property of liquids, influencing their behavior at microscopic levels. For instance, water’s surface tension allows small insects like the water strider to walk on its surface. However, the same force can be detrimental to fragile structures in microchip production. The manufacturing of these components involves numerous intricate steps, including wet processing, where even minor traces of liquid could compromise the integrity of the final product.
As Karpitschka explains, “For example, turning thin silicon disks, known as silicon wafers, into microchips requires several steps where the material must be wet, such as during the etching of transistors in acid baths.” The challenge lies in removing residual liquids without damaging these sensitive materials. Traditional methods, such as wiping or boiling, are inadequate and can leave contaminants behind.
Innovative Approach to Liquid Removal
To overcome these challenges, the research team explored a method that minimizes contact with the microstructures. They utilized the Marangoni force, which is generated by differences in surface tension across a surface. Karpitschka elaborates, “When adjacent areas have varying surface tensions, it creates a kind of ‘tug-of-war’ where the stronger side displaces the weaker one, effectively pulling liquids along.”
In their experiments, the researchers introduced additional liquid—specifically, alcohol with a lower surface tension than water. This vapor condenses on the existing liquid, generating the necessary tension difference to create a current. The researchers can then guide these currents across the surface, collecting remaining liquid into larger droplets, akin to raindrops coalescing on a windowpane.
This method promises to enhance the production efficiency of micro- and nanomaterials across various applications. By allowing for the gentle drying of small surface structures, it minimizes the risk of damage, thereby supporting the fabrication of more reliable electronic components.
The research, conducted by Karpitschka and his team, including Ze Xu, highlights a significant advancement in the field of materials science. Their findings not only improve current manufacturing processes but also pave the way for future innovations in the production of complex microstructures.
For more details, refer to the full study: “Vapor-mediated wetting and imbibition control on micropatterned surfaces,” published in Proceedings of the National Academy of Sciences.
