INSP PolyvinylAcetate Hexylthiophene piezoelectric force microscopy EPFL ContactModeDot PtfeFilter Gallium PinpointNanomechanicalMode OpticalModulator LowDensityPolyethylene HiVacuum CrystalGrowing multi_layer INSPParis BiasMode Adhesion small_scan nanomechanical optoelectronics HBN Piranha HighResolution CrossSection neodymium_magnets LateralPFM NanoLithography Indent Steps TemperatureControlledAFM Protein ForceMapping Jason Microchannel LDPE