My work on the coupling of lateral forces into qPlus force measurements got me thinking about the best way to avoid this problem. By making an AFM sensor based on a beam clamped at both ends with a tip in the middle, the tip’s motion (and hence the measured force) will always be normal to the beam. The design becomes more interesting when you consider the second vibrational mode of the beam, the tip is now at a node of the oscillation, and the tip apex will move parallel to the beam. This allows the sensor to work as both an AFM and an LFM sensor.
This work was published in Beilstein Jounrnal of Nanotechnology under the title: “Optimal geometry for a quartz multipurpose SPM sensor”
(The paper is open access).