Topological Microfluidics

State-of-the-art microfluidic techniques rely usually on an isotropic carrier fluid, the flow of which is modulated using morphological patterns on the microchannels, or application of external fields. Topological Microfluidics replaces the isotropic fluid by an anisotropic liquid crystal, and harnesses the interaction between flow and molecular ordering. We have demonstrated novel applications beyond the conventional isotropic microfluidics. For instance, we have created a flexible but versatile approach to guided transport of microscopic cargo in microfluidic devices. By tailoring the boundary conditions and the overall geometry, topological defects in the liquid crystal bulk phase were created at will, and were guided towards a specific target. The structure of defects emerging in the system, which are otherwise considered nuisance in applications, was used as a self-assembled system of soft rails, along which droplets containing the materials of interest could be transported. Topological microfluidics introduces a unique platform for targeted delivery of single particles, droplets, or clusters of such entities, paving the way to flexible micro-cargo concepts in microfluidic settings. Currently, we are exploring different facets of Topological Microfluidics in a range of fluidic and liquid crystalline systems.

The research
was embeddded in the Marie Curie Initial Training Network ’Hierarchy’ and carried out at the Max Planck Institute for Dynamics and Self-Organization, under the supervision of Dr. Christian Bahr and Prof. Dr. Stephan Herminghaus, in active collaboration with Prof. Dr. Jörg Enderlein of the Third Physics Institute, University of Göttingen.