Worcester_Polytechnic_Institute AnodizedAluminumOxide Ram Polytetrafluoroethylene piezoelectric force microscopy IMT_Bucharest molecules Treatment PS_LDPE Chloroform CaMnO3 Butterfly suspended_graphene Wonseok ring shape Polystyrene Ni81Fe19 Optic AdhesionEnergy Bismuth Tungsten_disulfide temp NTU PVA TemperatureControl KAIST multi_layer FrictionalForceMicroscopy Vanadate Carbon DeflectionOptics Cross-section Styrene FAFailureAnlaysis Piezoresponse