GaAs PtfeFilter SFAs MetalCompound aluminum_nitride ChemicalCompound Non-ContactMode H-BN UnivMaryland bias_mode Anneal PVAC HiVacuum Nanotechnology 2dMaterials Monisha MonoLayer Fiber Graphite Mechinical HardDisk Memory high_resolution LightEmiting 2-vinylpyridine ReflexLens KevlarFiber NanoLithography conductive SiWafer Regensburg Butterfly Sio2 MagneticForceMicroscopy piezoelectric force microscopy