A method of measuring properties of a sample, the method comprising: measuring a deflection of a cantilever of a COIFM; measuring a voltage at an actuator contacting the cantilever and configured to counteract the deflection of the cantilever; measuring a voltage at a scan signal source, wherein the scan signal source is communicably coupled to the piezotube and configured to move the piezotube along an X- and a Y-axis; measuring a voltage at a feedback controller, wherein the feedback controller is communicably coupled to the piezotube and configured to move the piezotube along a Z-axis; switching a switch from a first position to a second position; switching the switch to a third position; correlating at least one of the measurements to (i) a repulsive force, and (ii) an attractive force.