Raman Research Institute

Bangalore

Seminar

Title: Micro/Nano Scale Elastohydrodynamics and Reactive Transport in Porous Media

Speaker: Pratyaksh Karan (Geosciences Rennes University of Rennes 1)

Date & Time: Thursday, 7 August 2025 at 11:00am

Venue: Auditorium

Abstract: Elastohydrodynamics manifests as an important phenomenon in numerous micro/nano scale physical systems where flow occurs in presence of soft structures. An example of contemporary scientific relevance is fluid-mediated scanning probe microscopy (FM-SPM), an emerging tool to study delicate materials where a rigid probe is actuated perpendicular to and in proximity of a soft film, with the gap between them filled by a fluid. Developing a comprehensive mathematical model for the inherent elastohydrodynamics, we delineated the interplay of DLVO and solvation forces with elastohydrodynamics in FM-SPM, quantifying orders of magnitude magnification in the soft film deformation and the force response, exclusively due to these non-hydrodynamic forces. Furthermore, we also demonstrated that high frequency mode of operation enables diminution of these forces in comparison to hydrodynamic forces, confirming FM-SPM as an effective non-contact mechanical characterization tool for delicate materials. Beyond mechanical interactions, flows through micro/nano confinements are also hotbeds for reactive transport of dissolved solutes, which in turn plays a central role in a wide range of porous media systems and applications, e.g., chemotaxis in tumors, action of injected drugs, bioremediation of aquifers, etc. Exploring the interplay of the different transport processes, i.e., advection, diffusion and reaction, we delineated the exclusive impact of hydrodynamic dispersion on radially-advected reaction fronts by modelling the advection-dispersion-reaction equation, and, revealed the underlying phenomena driving the behavior of extensional flow reaction fronts when subjected to transient flow events by developing and operating lab-scale millifluidic Hele-Shaw and porous-media cells.

Join Zoom Meeting:

https://us02web.zoom.us/j/82371157188?pwd=8HxlbbUxJJzAPrhTCxEQWUlAZ97JZW.1

Meeting ID: 823 7115 7188

Passcode: 771996

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