Epoxy Galfenol GranadaUniv MechanicalProperty Indent Nickel AlkaneFilm light_emitting flakes SurfaceOxidation Flake molecule kelvin probe force microscopy Vortex LiftHeight Semiconductor BTO Ptfe TipBiasMode NusEce Tin sulfide OpticalElement HighAspect Floppy VortexCore vertical_PFM Worcester_Polytechnic_Institute Bacterium ForceVolumeMapping Pore domain_switching Tin disulfide Topography Conductivity ScanningSpreadingResistanceMicroscopy