Related Experiment Video
Updated: Jul 16, 2026
10:13
A Microfluidic-based Hydrodynamic Trap for Single Particles
Published on: January 21, 2011
No-slip hydrodynamic boundary condition for hydrophilic particles
Christopher D F Honig1, William A Ducker
1Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria 3010, Australia.
Physical Review Letters
|March 16, 2007
Summary
Hydrodynamic forces on particles in viscous fluids are accurately predicted by lubrication theory, even at high speeds. Evanescent-wave measurements improved separation accuracy in these studies.
Area of Science:
- Fluid Dynamics
- Surface Science
- Physical Chemistry
Background:
- Understanding hydrodynamic forces is crucial for microparticle manipulation.
- Previous studies faced challenges in accurately measuring particle-surface separation.
Purpose of the Study:
- To measure and interpret forces between a glass particle and plate in viscous solutions.
- To validate theoretical models for hydrodynamic interactions at high strain rates.
Main Methods:
- Utilized evanescent-wave measurements for precise particle-plate separation.
- Employed concentrated aqueous sucrose solutions with varying viscosities (0.001–0.090 Pa·s).
- Investigated particle approach and separation at rapid rates (1–100 µm/s).
Main Results:
- Hydrodynamic forces were accurately described by Reynolds lubrication theory.
- A no-slip boundary condition was validated even at strain rates up to 250,000 s⁻¹.
- Evanescent-wave technique significantly reduced uncertainty in separation measurements.
Conclusions:
- Reynolds lubrication theory with a no-slip boundary condition is robust for predicting forces in viscous fluids.
- The study demonstrates a more accurate method for measuring particle-surface interactions.
- Findings have implications for microfluidics and colloid science.
More Related Videos
07:23Light-induced Patterning and Grafting for Slippery Surfaces based on Silane-coated Nanoporous Structures
Published on: November 14, 2025
11:51Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
Related Concept Videos
01:17Steady, Laminar Flow Between Parallel Plates
Understanding steady, laminar flow between parallel plates is essential for analyzing and designing flow in narrow rectangular channels, commonly found in various water conveyance and drainage systems. The Navier-Stokes equations govern fluid motion and are generally challenging to solve due to their nonlinearity. However, simplifications are possible in certain cases, like the steady laminar flow between parallel plates. For this scenario, we assume steady, incompressible, laminar flow.
01:28Magnetostatic Boundary Conditions
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
01:18Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
01:04Hydrostatic Pressure Force on a Curved Surface
Hydrostatic pressure on curved surfaces is a fundamental concept in fluid mechanics with broad applications in the civil engineering field. When fluid is in contact with a curved surface, as in a reservoir, dam, or storage tank, it exerts pressure that varies in magnitude and direction along the curved surface. To assess the total hydrostatic force exerted by the fluid on a curved structure, engineers typically isolate the fluid volume adjacent to the surface and analyze the forces acting on...
01:16Electrostatic Boundary Conditions
Consider an external electric field propagating through a homogeneous medium. When the electric field crosses the surface boundary of the medium, it undergoes a discontinuity. The electric field can be resolved into normal and tangential components. The amount by which the field changes at any boundary is given by the difference between the field components above and below the surface boundary.
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
01:27Electrostatic Boundary Conditions in Dielectrics
When an electric field passes from one homogeneous medium to another, crossing the boundary between the two mediums imparts a discontinuity in the electric field. This results in electrostatic boundary conditions that depend on the type of mediums the field propagates through.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.