Introduction to Molecular-Scale Understanding of Surface Tension

In this article, microscopic understanding of the surface tension are provided, which needs basic knowledge of thermodynamics, statistical mechanics as well as continuum mechanics. By introducing the intermolecular interaction potential and temperature definition, and by showing conceptual pictures including some results obtained by molecular dynamics simulations, the author hopes that the target readers of undergraduate level students can find fascinating aspects of surface tension as the boundary of macroscopic and microscopic physics.