MIT's New Microscope Creates Near-Real-Time Nanoscale Video of Chemical Reactions

State-of-the-art atomic force microscopes (AFMs) are designed to capture images of structures as small as a fraction of a nanometer — a million times smaller than the width of a human hair.

Atomic force microscopes typically scan samples using an ultrafine probe, or needle, that skims along the surface of a sample, tracing its topography, similarly to how a blind person reads Braille.
https://www.youtube.com/watch?v=VK_RDpLEQrQ&list=PLK2ccNIJVPpBTWAazlaPhTdWJcj0gtcPJ