Nanoscale IR spectroscopy typically employs a combination of Atomic Force Microscopy (AFM) and IR laser sources. The AFM tip acts as a local detector of the infrared absorption, enhancing the spatial resolution significantly. When the IR laser illuminates the sample, molecules within the sample absorb the IR light and undergo vibrational transitions. The AFM tip detects the localized thermal expansion or photothermal effect caused by these transitions, generating a high-resolution IR spectrum.
