WHERE Ω

One of the most important issues in the analysis of Force Microscopy experiments is the characterization of the geometry of the tip apex. This can be done directly by imaging the tip with scanning electron microscopy (SEM) or by using calibration samples together with different deconvolution techniques [1]. Here we propose a simpler method to determine the tip radius by measuring the electrostatic force between the tip and a flat metallic sample. Recent calculations [2] showed that the electrostatic force between a tip and a metallic surface can be approximated as