Polydimethylsiloxane Graphene small_scan Multiferroic_materials DNAProtein LeakageCurrent PatternedSapphireSubstrat Temasek_Lab Flake Layer Litho Current Hole PS_PVAC Bacterium gallium_nitride Optoelectronic PolyStylene TungstenThinFilmDeposition Al2O3 FrictionalForce Wafer CuParticle Scratch Composite ContactModeDots Polyurethane biocompatible Stiffness Optical ItoGlass HBN AdhesionForce exfoliate TempControl