Electric Force Microscopy (EFM) is a secondary imaging mode derived from tapping mode that measures electric field gradient distribution above the sample surface. This is performed through lift mode. In EFM, a voltage may be applied between the tip and the sample. The cantilever’s resonance frequency and phase change with the strength of the electric field gradient and are used to construct the EFM image. For example, locally charged domains on the sample surface are mapped in a way that is similar to how MFM maps magnetic domains.