PolyvinylAcetate ContactModeDots Wang Dental MoirePattern Steps LightEmission Vortex FrictionalForceMicroscopy membrane TappingMode temp Solar silicon_oxide DOE PtfeFilter P3HT NTU PS_LDPE SThM Floppy Monisha Oxide Pinpoint PFM pulsed_laser_deposition lithography FrequencyModulation Terrace SrO SiWafer HfO2 Topography Insulator Liquid Piezo