ScanningThermalMicroscopy Titanate Pinpoint temperature_control lift_mode SrTiO3 ForceDistanceSpectroscopy WS2 Ananth small_scan Christmas 2-vinylpyridine Reading Gallium_Arsenide PinpointPFM Leakage BlockCopolymer STO Polystyrene ScanningSpreadingResistanceMicroscopy gallium_nitride Resistance CP-AFM Polymer Polyvinylidene biocompatible mechanical property PUR Trench cross section nanomechanical SAM AdhesionForce Electronics SoftSample