Quantitative measurement of fluid inertial effects in confined Brownian motion
Abstract
The hydrodynamic response of Brownian particles in liquids is fundamentally altered by inertial forces arising from unsteady momentum transport in the surrounding fluid. These forces are of two distinct types: the added mass and the history effect. While both are well understood in bulk and weakly-confined geometries, under deterministic driving, their respective behaviours under strong confinement and thermal fluctuations remain scarcely addressed, unclear and often entangled together. The goal of the present study is thus to fill this fundamental gap. The confinement-induced variations of the two distinct inertial contributions are separately investigated in the vicinity of a flat, rigid wall, using a combination of broadrange thermal colloidal-probe atomic-force-microscopy experiments, advanced numerical simulations and theoretical arguments. Specifically, the separation of the added-mass and history-force contributions is achieved through their different frequency-scaling signatures within the assumed form of the generalized dissipation coefficient. Our results pave the way towards a complete picture of Brownian motion at interfaces, in the lubrication regime, with direct relevance to nanofluidics and interfacial biophysics.
Related
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- Self-Avoidance Governs Re-entrant Coil-Globule Transition of Inertial Active Brownian Ring Polymers
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BibTeX
@misc{ferreira2026quantitative,
title = {{Quantitative measurement of fluid inertial effects in confined Brownian motion}},
author = {Quentin Ferreira and Pablo Palacios-Alonso and Harshit Joshi and Rafael Delgado-Buscalioni and Yacine Amarouchene and Thomas Salez},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.09193},
eprint = {2606.09193},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05646766v2},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Quantitative measurement of fluid inertial effects in confined Brownian motion
AU - Quentin Ferreira
AU - Pablo Palacios-Alonso
AU - Harshit Joshi
AU - Rafael Delgado-Buscalioni
AU - Yacine Amarouchene
AU - Thomas Salez
PY - 2026
DA - 2026/10/02
PB - HAL
DO - 10.48550/arxiv.2606.09193
UR - https://hal.science/hal-05646766v2
AB - The hydrodynamic response of Brownian particles in liquids is fundamentally altered by inertial forces arising from unsteady momentum transport in the surrounding fluid. These forces are of two distinct types: the added mass and the history effect. While both are well understood in bulk and weakly-confined geometries, under deterministic driving, their respective behaviours under strong confinement and thermal fluctuations remain scarcely addressed, unclear and often entangled together. The goal of the present study is thus to fill this fundamental gap. The confinement-induced variations of the two distinct inertial contributions are separately investigated in the vicinity of a flat, rigid wall, using a combination of broadrange thermal colloidal-probe atomic-force-microscopy experiments, advanced numerical simulations and theoretical arguments. Specifically, the separation of the added-mass and history-force contributions is achieved through their different frequency-scaling signatures within the assumed form of the generalized dissipation coefficient. Our results pave the way towards a complete picture of Brownian motion at interfaces, in the lubrication regime, with direct relevance to nanofluidics and interfacial biophysics.
ER -