We are currently on the verge of several breakthroughs in nanoscience and technology, and we need to prepare our citizenry to be scientifically literate about the microscopic world. Previous research shows that students' mental models of friction at the atomic level are significantly influenced by their macroscopic ideas. Most students see friction at the microscopic scale as due to the meshing of bumps and valleys and rubbing of atoms. Furthermore, for most students, what is true macroscopically should also be true microscopically. Friction provides a very good context for making students aware of the disparity between the macroscopic and microscopic worlds. In the proceeding sections we will present a series of activities that teachers can use to refine students' ideas of friction at the microscopic level. Several teaching interviews were conducted to develop and validate these activities and to establish the concepts/ideas that students adopt as they go through each of the activities.