Work

Partially substrateless microchannels for direct monitoring of interfacial dynamics in hydrophobic surfaces

Year: 2025

Type: article

Abstract: Superhydrophobic and liquid-infused surfaces are the most prominent techniques to achieve drag reduction in microchannels. However, they have specific drawbacks such as costly fabrication of complex and mechanically sensitive surfaces, surfaces susceptible to lubricant abrasion or involve hazardous chemicals. We present a partially substrateless microchannel whose upper wall features a large no-shear air/water meniscus at atmospheric pressure. On this wall, a self-assembled monolayer of hydrophobic alkyl silane was bonded covalently. Flow experiments reveal a drag reduction of up to 25% although only 4% of the wall fulfils the no-shear condition. These experiments demonstrated long-term stability and self-healing properties. Furthermore, White Light Interferometry (WLI) was used for direct monitoring of interfacial dynamics. By optical investigation of the full meniscus topography the contact-free evaluation of the spatially resolved static pressure distribution was possible. Conducted numerical simulations are in good agreement with the experimental findings and illustrate the drag reduction mechanism.

Source: Communications Engineering

DOI: 10.1038/s44172-025-00386-6

Authors: Ellen Bold, Sebastian Zimmermann, Clarissa Schönecker, Egbert Oesterschulze

Institutions: University of Kaiserslautern, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau

Language: English

Topic: Surface Modification and Superhydrophobicity

Subfield: Surfaces, Coatings and Films

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,190

Funder: Deutsche Forschungsgemeinschaft