ABSTRACT
Long-range nonbonded interactions of a fundamental and ubiquitous nature exist among all matter. These interactions are manifested at atomic, molecular, microscopic, and macroscopic length scales. They exist even when the interacting entities are electrically neutral (uncharged) and carry no electric or magnetic moments. Such interactions are always attractive in vacuum. The forces arising from these interactions are variously termed as dispersion forces, Casimir forces, or van der Waals forces. This chapter aims to provide a simple description of these interactions and forces, their importance in microuidic and nanouidic systems, commonly available techniques for their calculation, and a review of current status of our knowledge of these forces.
