PinpointPFM PhthalocyaninePraseodymium BFO Al2O3 PetruPoni_Institute Piezo Nanofiber Hexylthiophene flakes Subhajjit PpLdpe Multiferroic_materials piezoelectric force microscopy Hair Blood Led lift_mode Electical&Electronics Composite CeNSE_IISc Moire Gallium_Arsenide Barium_titanate Semiconductor Polyaniline Bismuth SmalScan exfoliate Writing Aluminium_Oxide oxide_layer dichalcogenide polyvinyl acetate ring shape STO