SICM AM-KPFM mechanical_property Mfm kelvin probe force microscopy LDPE VortexCore Inorganic Copolymer contact Temasek_Lab Conductive AFM Step UTEM ElectroChemical Fluoride Growing OpticalWaveguides P3HT InsulatorFilm self_assembly Phenanthrene ScanningKelvinProbeMicroscopy FrictionalForceMicroscopy Monisha Transparent MagneticForceMicroscopy food OpticalElement Conducting Nanofiber SoftSample Ram CeNSE_IISc Permalloy