kelvin probe force microscopy Glass TyphimuriumBiofilm LiBattery ferromagnetic Electronics I-VSpectroscopy CP-AFM Ni-FeAlloy Conductance Temasek_Lab SurfaceChange ring shape AnodizedAluminumOxide Biofilm Fendb PUR PolymerBlend Calcium Collagen BiasMode MolybdenumDisulfide doped Ni81Fe19 multi_layer Sio2 ScanningKelvinProbeMicroscopy Polymer LiquidImaging SPMLabs hydrocarbon Morphology HiVacuum LowDensityPolyethylene lithography