Polyurethane Force-distance ForceVolume EPFL Spincast gallium_nitride SrTiO3 TemperatureControl ForceMapping pulsed_laser_deposition Array HDD Gold Calcium 2dMaterials STM MembraneFilter molecular_beam Composition ReflexLens kelvin probe force microscopy Boron ElectroDeposition Phthalocyanine single_layer SiliconOxide Strontium PinpointNanomechanicalMode Blend StyreneBeads ScanningKelvinProbeMicroscopy PyroelectricDetector ForceVolumeImage heterojunctions IIT-chennai