How a blister heals

¹ Department of Chemical Engineering, Lehigh University - Bethlehem, PA 18015, USA
² School of Engineering and Applied Sciences, and Department of Physics, Harvard University Cambridge, MA, 02138, USA

^(a) mkc4@lehigh.edu

Received: 23 October 2013
Accepted: 22 November 2013

Abstract

We use experiments to study the dynamics of the healing of a blister, a localized bump in a thin elastic layer that is adhered to a soft substrate everywhere except at the bump. We create a blister by gently placing a glass cover slip on a PDMS substrate. The pressure jump across the elastic layer drives fluid flow through micro-channels that form at the interface between the layer and the substrate; these channels coalesce at discrete locations as the blister heals and eventually disappear at a lower critical radius. The spacing of the channel follows a simple scaling law that can be theoretically justified, and the kinetics of healing is rate limited by fluid flow, but with a non-trivial dependence on the substrate thickness that likely arises due to channelization. Our study is relevant to a variety of soft adhesion scenarios.