Adhesive contact of elastic spherical shells: Non-monotonic thickness dependence of pull-off force

The adhesive contact of spherical shells is a critical problem across multiple length scales. In this study, we investigate the adhesive contact between an elastic spherical shell and a rigid plane. Two independent approaches are employed: the JKR theory from an energy perspective, and a simulation-based method incorporating a traction-separation law. Our results reveal a non-monotonic relationship between pull-off force and shell thickness. Specifically, for relatively thick shells, the pull-off force decreases with decreasing thickness; however, below a critical thickness, this trend reverses, and the pull-off force begins to increase. Furthermore, we explore the underlying mechanisms responsible for this behavior and examine the influence of adhesion parameters on the overall response.