CP-AFM Galfenol small_scan SSRM Global_Comm GaN kelvin probe force microscopy BTO Worcester_Polytechnic_Institute India solar_cell Solution PhaseChange NUS Conductance AM-KPFM HOPG amplitude_modulation SrO Carbon DNAProtein Bacterium ContactModeDots dichalcogenide mono_layer Fluoride CuFoil TemperatureControllerStage Conduct Ptfe light_emitting Typhimurium single_layer INSP Cobalt-dopedIronOxide