STO SrO Chrome CalciumHydroxyapatite gallium_nitride polymeric_arrays Thermal Vacuum SoftSample ForceVolume semifluorinated_alkanes FM-KPFM ConductingPolymer SiliconOxide TCS SiWafer piezoelectric force microscopy ULCA Wonseok Polyvinylidene Worcester_Polytechnic_Institute Barium_titanate HydroGel LateralForceMicroscopy BFO GaN ForceVolumeMapping Semiconductor SingleCrystal MESA structure Pore Tape MagneticForce CopperFoil StyreneBeads