Surface Potential Microscopy (SPoM) is based on the macroscopic Kelvin method. SPoM is able to measure surface topography and surface potential (VDC) information simultaneously. Topography is acquired using TappingMode™ operation but with a conductive tip. The electrical information is extracted by applying AC and DC voltages to the tip. The total voltage acting on the tip is: V = VDC + VAC sin (Ω t). A dedicated feedback loop adjusts the DC voltage to the tip to zero the contact potential difference between the tip and surface at each pixel, making DC a measure of the surface potential. SPoM can be carried out using LiftMode™ or in a dual-frequency one-pass fashion.

Probes: