1.1k citations · 4.4k across the 30 of their papers we have counts for
21 papers · 1 filter
Microchannel flow of a shear-banding fluid: enhanced confinement effect and interfacial instability
P. Nghe, S. M. Fielding, P. Tabeling +1
Using a micro particle imaging velocity technique, we resolve for the first time the three dimensionnal structure of wormlike shear banding flows in straight microchannels. The stu…
A kinetic theory of plastic flow in soft glassy materials
Lyderic Bocquet, Annie Colin, Armand Ajdari
A kinetic model for the elasto-plastic dynamics of a flowing jammed material is proposed, which takes the form of a non-local -- Boltzmann-like -- kinetic equation for the stress d…
Stochastic Low Reynolds Number Swimmers
Ramin Golestanian, Armand Ajdari
As technological advances allow us to fabricate smaller autonomous self-propelled devices, it is clear that at some point directed propulsion could not come from pre-specified dete…
Modeling phase behavior for quantifying micro-pervaporation experiments
Michael Schindler, Armand Ajdari
We present a theoretical model for the evolution of mixture concentrations in a micro-pervaporation device, similar to those recently presented experimentally. The described device…
Mechanical Response of a Small Swimmer Driven by Conformational Transitions
Ramin Golestanian, Armand Ajdari
A conformation space kinetic model is constructed to drive the deformation cycle of a three-sphere swimmer to achieve propulsion at low Reynolds number. We analyze the effect of an…
Analytic results for the three-sphere swimmer at low Reynolds number
Ramin Golestanian, Armand Ajdari
The simple model of a low Reynolds number swimmer made from three spheres that are connected by two arms is considered in its general form and analyzed. The swimming velocity, forc…
Transverse transport of solutes between co-flowing pressure-driven streams for microfluidic studies of diffusion/reaction processes
Jean-Baptiste Salmon, Armand Ajdari
We consider a situation commonly encountered in microfluidics: two streams of miscible liquids are brought at a junction to flow side by side within a microchannel, allowing solute…
Propulsion of a molecular machine by asymmetric distribution of reaction--products
Ramin Golestanian, Tanniemola B. Liverpool, Armand Ajdari
A simple model for the reaction-driven propulsion of a small device is proposed as a model for (part of) a molecular machine in aqueous media. Motion of the device is driven by an…
Microfluidic Exploration of the Phase Diagram of a Surfactant/Water Binary System
Jacques Leng, Mathieu Joanicot, Armand Ajdari
We investigate the behaviour of a binary surfactant solution (AOT/water) as it is progressively concentrated in microfluidic evaporators. We observe in time a succession of phase t…
Giant amplification of interfacially driven transport by hydrodynamic slip: diffusio-osmosis and beyond
Armand Ajdari, Lyderic Bocquet
We demonstrate that "moderate" departures from the no-slip hydrodynamic boundary condition (hydrodynamic slip lengths in the nanometer range) can result in a very large enhancement…
Micro-evaporators for kinetic exploration of phase diagrams
Jacques Leng, Barbara Lonetti, Patrick Tabeling +2
We use pervaporation-based microfluidic devices to concentrate species in aqueous solutions with spatial and temporal control of the process. Using experiments and modelling, we qu…
Slow flows of yield stress fluids: complex spatio-temporal behaviour within a simple elasto-plastic model
Guillemette Picard, Armand Ajdari, Francois Lequeux +1
A minimal athermal model for the flow of dense disordered materials is proposed, based on two generic ingredients: local plastic events occuring above a microscopic yield stress, a…
Elastic consequences of a single plastic event : a step towards the microscopic modeling of the flow of yield stress fluids
Guillemette Picard, Armand Ajdari, Francois Lequeux +1
With the eventual aim of describing flowing elasto-plastic materials, we focus on the elementary brick of such a flow, a plastic event, and compute the long-range perturbation it e…
Diffuse-Charge Dynamics in Electrochemical Systems
Martin Z. Bazant, Katsuyo Thornton, Armand Ajdari
The response of a model micro-electrochemical system to a time-dependent applied voltage is analyzed. The article begins with a fresh historical review including electrochemistry,…
Effective interactions between inclusions in complex fluids driven out of equilibrium
Denis Bartolo, Armand Ajdari, Jean-Baptiste Fournier
The concept of fluctuation-induced effective interactions is extended to systems driven out of equilibrium. We compute the forces experienced by macroscopic objects immersed in a s…
Mechanical aging and non-linear rheology of concentrated colloidal suspensions: experimental facts and simple models
Armand Ajdari
Many colloidal systems display very non-Newtonian and solid-like behaviour when concentrated, a striking feature being the apparition of a yield stress. After recalling some basics…
Fluctuations of Fluctuation-Induced "Casimir" Forces
Denis Bartolo, Armand Ajdari, Jean-Baptiste Fournier +1
The force experienced by objects embedded in a correlated medium undergoing thermal fluctuations--the so-called fluctuation--induced force--is actually itself a fluctuating quantit…
Tracer diffusivity in a time or space dependent temperature field
Ramin Golestanian, Armand Ajdari
The conventional assumption that the self-diffusion coefficient of a small tracer can be obtained by a local and instantaneous application of Einstein's relation in a temperature f…
A simple model for heterogeneous flows of yield stress fluids
G. Picard, A. Ajdari, L. Bocquet +1
Various experiments evidence spatial heterogeneities in sheared yield stress fluids. To account for heterogeneities in the velocity gradient direction, we use a simple model corres…
Rheological Chaos in a Scalar Shear-Thickening Model
M. E. Cates, D. A. Head, A. Ajdari
We study a simple scalar constitutive equation for a shear-thickening material at zero Reynolds number, in which the shear stress σis driven at a constant shear rate \dotγand relax…
Transverse electrokinetic and microfluidic effects in micro-patterned channels: lubrication analysis for slab geometries
Armand Ajdari
Off-diagonal (transverse) effects in micro-patterned geometries are predicted and analyzed within the general frame of linear response theory, relating applied presure gradient and…