Surface Stress on Isotropic Solids under Dissipative Processes

Abstract

An attempt has been made in this paper to gather together theoretical results of important investigations of physical, chemical and mechanical properties of solid surfaces. In particular, we focus our attention on fundamental thermodynamical and mechanical quantities such as surface energy and stress which play a determining role in stability of micro- and nano-objects. Then, taking into account the non-autonomy of the surface, we define an extended pressure which includes irreversible effects due to mechanical and chemical processes in the surface and its underlying layer. This permits, more consistently, the proposition of a revisited Laplace formulation leading to a new interpretation of surface stress. Within the frame of homogeneous deformations, our theory now accounts for the aspect ratio and composition of the interfacial region as weighting factors of the variation of surface free energy with deformation of the surface.