vertical_PFM ThermalProperties Vortex NUS Phthalocyanine mechanical property Gong Wafer BariumTitanate Polymer piezoelectric force microscopy PVAC medical Insulator 2d_materials LMF Adhesive PS_PVAC blended polymers KevlarFiber Adhesion Fendb dielectric_trench Bismuth TipBiasMode Current MembraneFilter Magnets Conduct LeakageCurrent Mechanical ForceVolume non_contact MolybdenumDisulfide Conductivity