Eur. Phys. J. E (2018) 41: 36
https://doi.org/10.1140/epje/i2018-11643-6

Regular Article

Adhesion-induced fingering instability in thin elastic films under strain

¹ Department of Physics & Astronomy, McMaster University, Hamilton, L8S 4M1, Ontario, Canada
² Laboratoire de Physico-Chimie Théorique, UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005, Paris, France
³ Univ. Bordeaux, CNRS, LOMA, UMR 5798, F-33405, Talence, France
⁴ Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan

^* e-mail: dalnoki@mcmaster.ca

Received: 21 December 2017
Accepted: 28 February 2018
Published online: 22 March 2018

Abstract

In this study, thin elastic films supported on a rigid substrate are brought into contact with a spherical glass indenter. Upon contact, adhesive fingers emerge at the periphery of the contact patch with a characteristic wavelength. Elastic films are also pre-strained along one axis before the initiation of contact, causing the fingering pattern to become anisotropic and align with the axis along which the strain was applied. This transition from isotropic to anisotropic patterning is characterized quantitatively and a simple model is developed to understand the origin of the anisotropy.