polyvinyl acetate ScratchMode margarine Worcester_Polytechnic_Institute Monisha Korea UnivOfMaryland Solution Biofilm Dopped Conduct Sidewall Hexacontane Patterns Holes KelvinProbeForceMicroscopy IIT-chennai mechanical_property cross section piezoelectric force microscopy EFM Conducting Bmp Tin sulfide CP-AFM Chemical_Vapor_Deposition Hair Transparent Scratch Crystal Ni81Fe19 Formamidinium_lead_iodide suspended_graphene Lateral Piezoresponse