Random blisters on stickers: metrology through defects

TL;DR

This paper demonstrates how the analysis of blister defects in adhesive sheets can be used to infer material properties such as bending stiffness and adhesion energy through height profile measurements.

Contribution

It introduces a method to deduce material properties from blister height profiles, linking geometric features to physical parameters in random configurations.

Findings

Crest curvature proportional to an elasto-capillary length

Tip radius estimates the product of this length and sheet thickness

Results confirmed for realistic random blister configurations

Abstract

Blisters are commonly observed when an adhesive sheet is carelessly deposited on a plate. Although such blisters are usually not desired for practical applications, we show through model experiments on angular blisters how material properties can be deduced from height profile measurements. In particular the typical curvature of the crests is found proportional to an elasto-capillary length that compares the bending stiffness of the sheet with adhesion energy. In addition, the radius of the tip allows to estimate the product of this length with the thickness of the sheet. The relevance of these results to realistic random configurations is finally confirmed.