A scanning probe system and method for using the same are disclosed. The system includes a probe that interacts with a specimen. The probe is caused to vibrate at a first frequency of the probe. A probe deflection signal indicative of an oscillation amplitude of the probe is generated and used to set the z-position probe position to maintain a property of the probe deflection signal at the first frequency at a predetermined value. A probe signal, having a DC and an AC component is applied between the specimen and the probe. The amplitude of a frequency component of the deflection signal at a mixing frequency of the first frequency and the second frequency is measured and used to generate an image or adjust the DC component.