Peeling from a patterned thin elastic film

TL;DR

This study investigates how patterned thin elastic films influence crack initiation and propagation during peeling, revealing that incisions increase fracture toughness through cavitation bubble nucleation and coalescence.

Contribution

It introduces a theoretical framework explaining crack behavior in patterned elastic films and provides a design criterion to enhance interfacial fracture toughness.

Findings

Crack initiation requires higher load on patterned films than smooth surfaces.

Multiple incisions cause intermittent crack propagation.

Cavitation bubble dynamics underpin crack nucleation and growth.

Abstract

Inspired by the observation that many naturally occurring adhesives arise as textured thin films, we consider the displacement controlled peeling of a flexible plate from an incision-patterned thin adhesive elastic layer. We find that crack initiation from an incision on the film occurs at a load much higher than that required to propagate it on a smooth adhesive surface; multiple incisions thus cause the crack to propagate intermittently. Microscopically, this mode of crack initiation and propagation in geometrically confined thin adhesive films is related to the nucleation of cavitation bubbles behind the incision which must grow and coalesce before a viable crack propagates. Our theoretical analysis allows us to rationalize these experimental observations qualitatively and quantitatively and suggests a simple design criterion for increasing the interfacial fracture toughness of adhesive films.