Atomic force microscope-based infrared spectroscopy (AFM-IR) has been developed in recent years providing extremely high spatial resolution chemical characterization and imaging. The technique is based on the combination of a pulsed tunable infrared laser with an atomic force microscope. The AFM provides high spatial resolution images of the topography of the sample surface as well as measurements of other material properties available using the broad range of Scanning Probe Microscope techniques. The AFM probe can then be registered to features within the AFM image and used to measure the local thermal expansion of nanoscale regions of a sample resulting from the absorption of the pulsed infrared radiation. The AFM-IR technique, because the signal directly relates to absorption, provides a robust way to obtain interpretable IR spectra at spatial resolution scales well below the diffraction limit. In addition, the availability of microfabricated AFM probes with an embedded heater has allowed the development of a technique where small quantities of material are thermally desorbed from a sample surface for subsequent ionization and analysis by mass spectrometry. This atmospheric pressure technique, called AFM-MS, allows for multimodal measurements where the topography and mechanical properties of a sample can be analyzed using the AFM followed by chemical analysis with the mass spectrometer.<br/>Due to the high spatial resolution of both of these techniques they can be used for the chemical identification of small volumes of material, analysis of thin films or defects. Their utility in the analysis of multiple layers in paintings or prints will be discussed.

Nanoscale chemical analysis using AFM based IR spectroscopy and mass spectrometry

251st National Meeting (2016)

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