Intermodulation Frictional Force Microscopy (ImFFM)

(ImFFM) uses torsional resonance to achieve very high tip velocity ~ 5 cm/sec while measuring frictional forces with very high spatial resolution ~ 10 nm. At each image pixel you can observe how conservative and dissipative lateral force depends on the amplitude of tip oscillation. As the sliding velocity increases there is a transition from stick-slip to free-sliding friction.

See publication

ImFFM on HOPG. Dynamic force quadrature curves F<sub>I<sub>(A) and F<sub>Q<sub>(A) are shown at three pixels marked in the image. The bands in the image are due to changing the load force by changing the feedback setpoint, where darker corresponds to higher load force.   The scan size is 1um.