Patterns, Forces and Metastable Pathways in Debonding of Elastic Films

TL;DR

This paper investigates the fundamental mechanisms of debonding in elastic films, revealing how metastable patterns and energy barriers influence adhesion hysteresis and reduce debonding forces.

Contribution

It uncovers the role of metastable nanocavities and bridges in soft interface debonding, explaining hysteresis and lower adhesion strengths through energy barrier analysis.

Findings

Metastable patterned configurations cause hysteresis in debonding.

Energy barriers separate metastable states from complete debonding.

Pattern formation lowers the force required for debonding.

Abstract

The letter resolves several intriguing and fundamental aspects of debonding at soft interfaces, including the formation and persistence of regularly arranged nanocavities and bridges, ``adhesion-debonding hysteresis'', and vastly lower adhesive strengths compared to the absence of pattern formation. The analysis shows the hysteresis to be caused by an energy barrier that separates the metastable patterned configurations during withdrawal, and the debonded state. The metastable morphological pathways involving cavitation and peeling of contact zones engender substantially lower debonding forces.