Mfm single_layer CuFoil PolyvinylideneFluoride DNAProtein Magnetic PpLdpe Resistance hydrocarbon Piezo Photovoltaics Adhesive FM-KPFM CeNSE_IISc Chloroform SmallScan Cell VerticalPFM F14H20 Jason epitaxy LiftHeight ScanningKelvinProbeMicroscopy #Materials StyreneBeads Fujian NeodymiumMagnets Pipette Gallium SoftSample PS_LDPE small_scan FrictionForce Polyethylene molecule