How Geometry Controls the Tearing of Adhesive Thin Films on Curved Surfaces

TL;DR

This paper investigates how the curvature of substrates influences the shape and tearing behavior of adhesive thin films, revealing that geometry governs flap morphology through experimental and theoretical analysis.

Contribution

It introduces a geometric framework explaining how substrate curvature determines tear shapes in adhesive thin films, supported by experiments and models.

Findings

Tear shapes vary with substrate curvature, including triangular, elliptic, acuminate, and spatulate forms.

Flap morphology is governed by simple geometric rules.

Experimental and theoretical results are consistent in explaining tear behavior.

Abstract

Flaps can be detached from a thin film glued on a solid substrate by tearing and peeling. For flat substrates, it has been shown that these flaps spontaneously narrow and collapse in pointy triangular shapes. Here we show that various shapes, triangular, elliptic, acuminate or spatulate, can be observed for the tears by adjusting the curvature of the substrate. From combined experiments and theoretical models, we show that the flap morphology is governed by simple geometric rules.