Adhesive Single and Multi-asperity Contacts

Adhesion plays a fundamental role in contact mechanics, particularly when soft materials, e.g., elastomers and gels, are involved. The current development of technologies that involve soft robots, human–robot interactions, grippers, and manipulators are pushing the research towards a better understanding of how to model and simulate soft adhesive contacts. In this article, we first review the fundamental theories for single asperity adhesion of Johnson–Kendall–Roberts (JKR) and of Derjaguin–Muller–Toporov (DMT), as they provide the fundamental understanding of soft adhesive contact mechanics. Secondly, some of the phenomena influencing macroscopic adhesion are explored, i.e., topography of the contacting surfaces, material viscoelasticity, external normal excitations, shear loads, and interfacial roughness. Fundamental models, followed by classical and more recent literature results, are discussed for each phenomenon, clarifying how macroscopic adhesion is affected. Understanding these effects is essential for predicting interfacial performance in in a wide range of applications including biomimetic adhesives, tire–road interactions and microelectromechanical systems (MEMS).