Ram Christmas Optoelectronic Graphene China NUSNNI Pipette ScanningTunnelingMicroscopy biocompatible LeakageCurrent frequency_modulation LithiumNiobate PinpointPFM UTEM Chemical Vapor Deposition Copolymer ForceVolumeImage FailureAnlaysis CrossSection cannabinoid CeNSE_IISc Cancer Alloy plastic Gold Bacteria Optical graphene_hybrid FrictionalForceMicroscopy Conductivity molecules LMF RedBloodCell mechanical_property piezoelectric force microscopy