Cracking the capillary code: towards mesoscopic self-assembly and functional micromachines

Professor Nicolas Vandewalle, University of Liège Cambridge Fluids Network - fluids-related seminars 31 January 2025 4:00pm MR2 Self-assembly, a spontaneous process driven by thermal agitation and intermolecular interactions, is crucial for the formation and folding of complex macromolecules, with profound implications for chemistry and biology. While extensively studied at the molecular level, capillary-driven self-assembly has emerged as a promising approach for constructing structures at the mesoscopic scale, bridging the gap between classical bottom-up and top-down fabrication methods. Operating between 10 micrometers to 10 millimeters, this approach has, over two decades, largely produced regular or simplistic structures. This work leverages experimental and statistical physics to unveil methodologies for controlling subtle capillary interactions, enabling the design of intricate and highly complex structures. We demonstrate how these mesoscopic systems act as analogs for molecular phenomena, such as folding, lock-and-key mechanisms, and crystallization processes. Furthermore, by incorporating magnetic actuation, we explore the dynamic self-assembly of functional micromachines. These micromachines present potential applications in interface cleaning, particle sorting, and targeted transport, underscoring the transformative possibilities of capillary-driven systems for soft robotics and materials science.