Permalloy Layer Change FrictionalForce HexacontaneFilm Hexatriacontane contact biocompatible PS_PVAC temp_control hydrocarbon IMT_Bucharest Chungnam_National_University non_contact organic_polymer Ferroelectric fluorocarbon C_AFM Floppy Neodymium Liquid graphene_hybrid CaMnO3 Defect BoronNitride Scratch align Barium_titanate CP-AFM Dimethicone Terrace Ananth Varistor margarine Vacuum