When two miscible liquids meet, transient composition gradients across their boundary generate an effective interfacial tension. This gives rise to complex interfacial flow dynamics governed by tightly coupled mass and momentum transport: a fundamental problem with broad implications in microfluidics, active mixing, and soft matter physics. In this project, the student will investigate these interfacial flows through a combination of precision experiments and physical modelling. You will design and prototype custom millifluidic channels (using3D printing and microfabrication, no prior knowledge about it required) and perform micro-PIV measurements on a state-of-the-art inverted fluorescence microscope to map local velocity fields at the interface. Depending on the candidates background, the experimental work can be complemented by analytical scaling laws and calculations or numerical simulations.