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Photothermally excited force modulation microscopy for broadband nanomechanical property measurements



Ryan B. Wagner, Jason P. Killgore


We demonstrate photothermally excited force modulation microscopy (PTE FMM) for mechanical property characterization across a broad frequency range with an atomic force microscope (AFM). Photothermal actuation allows for an AFM cantilever driving force that varies smoothly as a function of frequency, thus avoiding the problem of spurious resonant vibrations that hinder piezoelectric actuation schemes. A complication of PTE FMM is that the sub-resonance cantilever vibration shape is fundamentally different compared to piezoelectric actuation. By directly measuring the vibrational shape of the cantilever, we show that PTE FMM is an accurate nanomechanical characterization method. PTE FMM enables the characterization of frequency sensitive specimens such as polymers and biomaterials with frequency range limited only by the resonance frequency of the cantilever and the low frequency limit of the AFM.
Applied Physics Letters


AFM, Nanomechanics, Force Modulation, Photothermal


Wagner, R. and Killgore, J. (2015), Photothermally excited force modulation microscopy for broadband nanomechanical property measurements, Applied Physics Letters, [online], (Accessed July 21, 2024)


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Created November 18, 2015, Updated February 19, 2017