Lateral capillary forces

Lateral capillary forces ensuing from perturbed fluid menisci are pivotal to many important technologies, including capillary self-alignment and self-assembly of heterogeneous microsystems. This chapter presents a comprehensive study of the quasi-statics of lateral capillary forces arising from a constrained cylindrical fluid meniscus subjected to small lateral perturbations. After a contextual literature review, we describe a novel experimental apparatus designed to accurately characterize such a fundamental system. We then reproduce our experimental data on lateral meniscus forces and stiffnesses by means of both a novel analytical model and a finite element model. The agreement between our measurements and our models validate earlier reports and provides a solid foundation for the applications of lateral capillary forces to microsystems handling and assembly.