AFM and its IR coupling: surface chemistry and topography

AFM-IR, developed some fifteen years ago at the Institut de Chimie-Physique at the University of Paris-Saclay, combines the high spatial precision of atomic force microscopy (AFM) with the chemical analysis capability of infrared (IR) spectroscopy. This technique makes it possible to map the chemical composition of samples according to their IR signature with a resolution of the order of a few tens of nm. This makes it possible to simultaneously analyse the morphology, topography and chemical composition of samples. This technique has applications in materials science and biology.


This coupling uses the period of contact between the tip and the sample to acquire the mechanical deformation of the lever caused by the thermal expansion induced by the emission of infrared pulses. The wavelengths absorbed can be used to determine the nature of the bond and thus the chemical composition of the sample. It can be used to explore spatial scales and spectral resolutions that are inaccessible to conventional infrared microscopy techniques.

In the field of biology, IR-MFA enables chemical spectroscopy to be carried out at the sub-cellular level, opening up new perspectives for the analysis of human tissues and micro-organisms. It also has applications in the study of polymers and other materials.