Wettability control of droplet durotaxis

TitleWettability control of droplet durotaxis
Publication TypeJournal Article
Year of Publication2018
AuthorsBueno, J, Bazilevs, Y, Juanes, R, Gomez, H
JournalSoft Matter
Issue8
Pagination1417 - 1426
Date PublishedJan-01-2018
ISSN1744-683X
Abstract

Durotaxis refers to cell motion directed by stiffness gradients of an underlying substrate. Recent work has shown that droplets also move spontaneously along stiffness gradients through a process reminiscent of durotaxis. Wetting droplets, however, move toward softer substrates, an observation seemingly at odds with cell motion. Here, we extend our understanding of this phenomenon, and show that wettability of the substrate plays a critical role: while wetting droplets move in the direction of lower stiffness, nonwetting liquids reverse droplet durotaxis. Our numerical experiments also reveal that Laplace pressure can be used to determine the direction of motion of liquid slugs in confined environments. Our results suggest new ways of controlling droplet dynamics at small scales, which can open the door to enhanced bubble and droplet logic in microfluidic platforms.

URLhttp://xlink.rsc.org/?DOI=C7SM01917C
DOI10.1039/C7SM01917C
Short TitleSoft Matter