Noninvasive determination of optical lever sensitivity in atomic force microscopy
نویسندگان
چکیده
Atomic force microscopes typically require knowledge of the cantilever spring constant and optical lever sensitivity in order to accurately determine the force from the cantilever deflection. In this study, we investigate a technique to calibrate the optical lever sensitivity of rectangular cantilevers that does not require contact to be made with a surface. This noncontact approach utilizes the method of Sader et al. Rev. Sci. Instrum. 70, 3967 1999 to calibrate the spring constant of the cantilever in combination with the equipartition theorem J. L. Hutter and J. Bechhoefer, Rev. Sci. Instrum. 64, 1868 1993 to determine the optical lever sensitivity. A comparison is presented between sensitivity values obtained from conventional static mode force curves and those derived using this noncontact approach for a range of different cantilevers in air and liquid. These measurements indicate that the method offers a quick, alternative approach for the calibration of the optical lever sensitivity. © 2006 American Institute of Physics. DOI: 10.1063/1.2162455
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