Microfluidics: The no-slip boundary condition

TL;DR

This paper reviews recent experimental, numerical, and theoretical studies on the no-slip boundary condition in fluid mechanics, highlighting the complex interplay of factors at the liquid-solid interface that could challenge traditional assumptions.

Contribution

It synthesizes recent research showing the potential violations of the no-slip boundary condition and the complex factors influencing fluid behavior at interfaces.

Findings

The no-slip boundary condition can be violated under certain conditions.

Multiple physico-chemical parameters influence slip behavior.

Recent studies suggest a more complex interface physics than traditionally assumed.

Abstract

The no-slip boundary condition at a solid-liquid interface is at the center of our understanding of fluid mechanics. However, this condition is an assumption that cannot be derived from first principles and could, in theory, be violated. We present a review of recent experimental, numerical and theoretical investigations on the subject. The physical picture that emerges is that of a complex behavior at a liquid/solid interface, involving an interplay of many physico-chemical parameters, including wetting, shear rate, pressure, surface charge, surface roughness, impurities and dissolved gas.