A discussion on "generality of shear thickening in dense suspensions"

TL;DR

This paper discusses the conditions under which shear thickening occurs in dense suspensions, highlighting that external electric or magnetic fields can induce phase changes that affect shear thickening behavior.

Contribution

It challenges the universality of shear thickening in dense suspensions by examining the effects of high electric/magnetic fields on ER and MR fluids.

Findings

Shear thickening can be masked by yield stress in dense suspensions.

High electric/magnetic fields induce phase changes affecting shear thickening.

Shear thickening behavior varies with external field application.

Abstract

In a recent Nature Materials article, Brown et al. reported a generality of shear thickening in dense suspensions and demonstrated that shear thickening can be masked by a yield stress and can be recovered when the yield stress is decreased to below a threshold. However, the generality of the shear thickening reported in the article may not be necessary true when a high electric/magnetic field is applied on an ER/MR fluid. Shear thickening of ER fluid and MR fluid under high electric/magnetic fields at low shear rates, indicating an obvious phase change inside the dense suspensions has been observed.