epitaxy Ucl Optic mechanical_property cannabinoid vertical_PFM F14H20 mono_layer EFM Forevision AdhesionEnergy ForceDistanceSpectroscopy fluoroaalkane PECurve Galfenol UnivMaryland Pyroelectric IcelandSpar CVD Pore Neodymium Pvdf Ito OpticalModulator LateralPFM Hexatriacontane suspended_graphene TransitionMetal EPFL mechanical property cooling PUR temp_control atomic_steps NUS_Physics