Rapid online quantification of tip-sample interaction for high-speed dynamic-mode atomic force microscope imaging

This paper presents a numerical-experimental integrated framework for rapid online estimation of the tip sample interaction forces for high speed AFM dynamic imaging. Quantifying the tip-sample interaction in AFM dynamic imaging is crucial towards achieving high-speed dynamic-mode AFM imaging with minimized tip-sample forces, particularly when imaging live biological samples in liquid media. Large tip-sample interactions can result in sample deformation or even destruction of the live biological samples. In this article, we propose an ultra-fast inversion strategy based on parallel algorithms implemented on Graphical Processing Units (GPUs). The tip-sample interaction estimation problem is posed as an inverse problem and is solved in near-real time using GPUs. We investigate several cost-functional formulations to ensure quality of reconstruction while maintaining a high rate of reconstruction. The computational scheme is verified with preliminary experimental results.his paper presents a numerical-experimental integrated framework for rapid online estimation of the tip sample interaction forces for high speed AFM dynamic imaging. Quantifying the tip-sample interaction in AFM dynamic imaging is crucial towards achieving high speed dynamic-mode AFM imaging with minimized tip-sample forces, particularly when imaging live biological samples in liquid media. Large tip-sample interactions can result in sample deformation or even destruction of the live biological samples. In this article, we propose an ultra-fast inversion strategy based on parallel algorithms implemented on Graphical Processing Units (GPUs). The tip-sample interaction estimation problem is posed as an inverse problem and is solved in near-real time using GPUs. We investigate several cost-functional formulations to ensure quality of reconstruction while maintaining a high rate of reconstruction. The computational scheme is verified with preliminary experimental results.