NUS_Physics Piezoelectric BFO Lateral Domain Etch Array BariumTitanate PtfeMembrane nanomechanical fluorocarbon FAFailureAnlaysis #EC AAO SmalScan vertical_PFM AM_KPFM Piezo TipBiasMode MembraneFilter Tungsten ElectroDeposition Insulator Holes HighAspect LateralPFM CalciumHydroxide AlkaneFilm EPFL Polydimethylsiloxane Stiffness LogAmplifier Vac contact dichalcogenide