Coated active cantilever probes for use in topography imaging in opaque liquid environments, and methods of performing topography imaging

An active probe, comprising:

• a substrate, the substrate including a cantilever having a base region and a tip region;
• a thermomechanical actuator associated with the cantilever and configured to cause the cantilever to deflect;
• a piezoresistive stress sensor disposed on the cantilever at the base region and configured to measure deflection of the cantilever at the tip region;
• and
• a thin coating disposed on the cantilever and the piezoresistive stress sensor, the coating being bonded to the substrate, thermally conductive, and having a thermal resistance, in which a thermal time constant τ is less than 1/ƒ, where ƒ is a cantilever resonance frequency,
• wherein the thin coating is configured to have a negligible impact, or no impact, on at least one of a resonance frequency or a maximum output amplitude on the cantilever and the piezoresistive stress sensor, the negligible impact being characterized by at least one of the thin coating increasing the resonance frequency by less than about 11% or decreasing the maximum output amplitude less than about eleven-fold,
• wherein the thin coating comprises a photoresist identifiable as “Positiv 20.”