PinpointPFM Formamidinium_lead_iodide IIT-chennai MLCC TappingMode TemperatureControllerStage polyvinyl acetate Wonseok PECurve CalciumHydroxide optoelectronics PolyimideFilm Polyvinylidene_fluoride ito_film MonoLayer TPU Tin disulfide Hafnium_dioxide flakes strontiu_titanate MagneticPhase Hydroxyapatite Foil pinpoint mode UnivCollegeLondon HexagonalBoronNitride CaMnO3 MESA structure ring shape Mechinical InsulatorFilm AM-KPFM Copolymer ForceVolumeMapping layers