High-speed atomic force microscopy combined with a local excitation setup for photoactive materials

High-speed atomic force microscopy (HS-AFM) is a powerful tool for observing nanoscale structures and motions as a movie with high spatial (~1 nm) and temporal (10 frames per second) resolutions. Recent advancements have led to the development of a tip-scan stand-alone HS-AFM combined with an optical microscope, enhancing its capability in various fields. A promising application is the observation of photoactive materials such as azo-polymers, which is important for optical applications because of their unique nanoscale motion under light irradiation. In this study, we constructed a tip-scan HS-AFM combined with a local laser excitation setup for photoactive materials, allowing HS-AFM observations of azo-polymers under focused laser irradiation. We successfully observed the azo-polymer deformation dynamics under laser irradiation by HS-AFM. Moreover, real-time topographic line profile analyses facilitated precise investigations of morphological changes. This demonstration highlights the potential of HS-AFM for expanding its application to a broader range of material science.