Regensburg 2016 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 48: Posters - Bioimaging and Spectroscopy

BP 48.18: Poster

Mittwoch, 9. März 2016, 17:00–19:00, Poster C

Photothermal Excitation for Reliable and Quantitative High-resolution AFM imaging and force spectroscopy — •Florian Johann, Aleksander Labuda, Deron Walters, Maarten Rudgers, Jason Cleveland, and Roger Proksch — Asylum Research, an Oxford Instruments Company, Wiesbaden, Germany

Photothermal excitation is an alternative method for exciting a cantilever by heating/cooling the base of the cantilever to drive the cantilever. Photothermal excitation results in repeatable, accurate and time-stable cantilever tunes. Therefore, the setpoint remains truly constant while imaging, preventing tip crashes, or unwanted tip retractions. True atomic resolution images of calcite in water were made for hours with no user intervention, testifying to the stability of photothermal excitation. Unlike other specialized drive methods, photothermal excitation is compatible with almost any cantilever and with all AFM techniques. Furthermore, because the photothermal tune represents the true cantilever transfer function, existing AFM theories can be applied to accurately recover conservative and dissipative forces between the tip and the sample. This is especially important for force spectroscopy, dissipation studies, as well as the frequency modulation AFM techniques.