SICM margarine Co/Cr/Pt Insulator Worcester_Polytechnic_Institute PolyimideFilm Ananth Scratch TemperatureControlledAFM EPFL InsulatorFilm semifluorinated_alkanes PtfeMembrane ElectroChemical LiquidCell LFM ring shape Metal IndiumTinOxide SSRM AtomicLayer Corrosion DOE Optic Polydimethylsiloxane 2d_materials PinpointNanomechanicalMode Fendb Wang fluoroaalkane Sapphire CrAu CBD Boundary Dimethicone