SPMLabs MembraneFilter NUS_NNI_Nanocore epitaxy Ecoli FAPbI3 AtomicSteps frequency_modulation Non-ContactMode Vinylpyridine Tungsten Forevision Iron Mfm Gallium Electrical&Electronics Edwin semifluorinated_alkanes LFM molecules ForceMapping Transparent HACrystal Sperm Fet Temasek_Lab FM_SKPM tip_bias_mode Ptfe AM_SKPM FrictionalForceMicroscopy INSP PFM mechanical_property KPFM