Fluid Seminar: Ranjan Ganguly (Jadavpur University, India)

  • Culture scientifique
Publié le 18 octobre 2023 Mis à jour le 27 octobre 2023

le 20 octobre 2023

Institut de Physique de Nice
Conference room 1+2

Capillary-driven fluidic transport on wettability-engineered surfaces: From affordable healthcare to sustainability solutions

Fluid seminar


With the advent of technology, there is a rapidly growing trend towards device miniaturization in several fields of engineering. A wide range of engineering applications, ranging from bioanalytical and biomedical devices to thermal management in electronics devices, is progressively seeking fluid transport at reduced length scale. Open microfluidics offers a new paradigm of droplet-based fluidic transport, where individual droplets, a train of droplets or an open jet of liquid is manipulated on a substrate, entailing certain operational advantages. However, achieving even the simplest microfluidic tasks in a controlled fashion on an open surfaces remains a challenge because of the absence of any flow conduits, pumps and valves. In general, a surface microfluidic platform for bioanalytical applications would warrant that the device is capable of directional transport, metered dispensing, mixing and splitting of the sample liquid without the need for any external power supply. Capillary-driven transport of liquid droplets and jets using spatial gradients and patterns in the underlying substrate-wettability has shown promise in achieving such transport. Liquid droplets on such wettability-engineered surfaces experience an unbalanced surface force in the direction of increasing wettability, leading to fluid mobilization on the substrate. In the first part of the talk, the underlying mechanism of such transport, and its use in the context of point of care (PoC) diagnostics will be discussed. A few relevant methods of surface fabrication will also be discussed which are facile, substrate independent, and hence can be realized on metal, silicon, glass, polymer or even paper. The second part of the talk will describe how such capillary-driven liquid transport on strategically wettability-patterned substrates can be leveraged to enhance atmospheric water capture via condensation, jet-impingement cooling, or even atmospheric and industrial fog harvesting.