Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
SYDW 1.5: Hauptvortrag
Donnerstag, 19. März 2020, 17:15–17:45, HSZ 02
Droplet durotaxis and engulfment on yielding viscoelastic gels — •Anne Juel — Department of Physics & Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
Durotaxis refers to the spontaneous motion of objects along stiffness gradients of the supporting substrate. For example, individual cells have the ability to detect substrate stiffness and usually migrate up rigidity gradients. In contrast, droplet durotaxis due to elasto-capillary interaction with soft substrates, leads to droplet migration down rigidity gradients towards the softer regions of the substrate. We perform experiments in which we explore droplet durotaxis in the limit of very soft PDMS substrates, where the cross-linked matrix of the gel may yield under the capillary stresses exerted by the sessile droplet. When we position an individual droplet on such a gel layer with a constant depth gradient, we find that the droplet moves towards the softest parts of the gel layer while also sinking into the gel and that droplet durotaxis is much faster when engulfment is associated with the motion. We explore the role of elastic forces in this process by comparing durotaxis on viscoelastic gels with engulfment into substrates of highly viscous Newtonian fluids.