By: Bede Pittenger
This application note discusses HarmoniX, a new mode of atomic force microscopy that extends these advantages even further, enabling higher resolution at higher speed while retaining the nondestructive, low-force qualities that make TappingMode AFM so popular. While contact mode force curves are typically easier to interpret than TappingMode phase data, tapping mode has the advantages of lower average normal forces, no lateral force, and relatively high speed. Recently, Ozgur Sahin (Rowland Institute at Harvard University) showed that by measuring the torsional amplitude at exact integer multiples (harmonics) of the tapping drive frequency, it is possible to extract the variation in force between the tip and the sample when the tip goes through a period of the tapping oscillation.