Two Simple Classroom Demonstrations for Scanning Probe Microscopy Based on a Macroscopic Analogy

This article describes two simple classroom demonstrations that illustrate the principles of scanning probe microscopy (SPM) based on a macroscopic analogy. The analogy features the bumps in an egg carton to represent the atoms on a chemical surface and a probe that can be represented by a dwarf statue (illustrating an origin of the prefix “nano”), a plastic bottle, or a glass. The demonstrations allow students to visualize certain physical aspects of SPM, such as probing “hilly” atoms on a surface using changes in distance between probe and atoms. Both demonstrations are appropriate to introduce SPM into high school or undergraduate science education.