title: Molecular and nanoscale compositional contrast of soft matter in liquid: interplay between elastic and dissipative interactions.
abstract: We demonstrate that the phase contrast observed with an amplitude modulation atomic force microscope depends on two factors, the generation of higher harmonics components and the energy dissipated on the sample surface. Those factors are ultimately related to the chemical composition and structure of the surface. Our findings are general, but they specifically describe the results obtained while imaging soft materials in liquid. Molecular resolution experiments performed on a protein membrane surface in liquid confirm the theory.
authors.affiliation: IMM-Instituto de Microelectrónica de Madrid, CSIC, Isaac Newton 8, Tres Cantos, 28760 Madrid, Spain.
authors.forename: Amir F
authors.initials: AF
authors.lastname: Payam
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Ramos
authors.forename: Ricardo
authors.initials: R
authors.lastname: Garcia
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D055119:Elastic Modulus; D004735:Energy Transfer; D006244:Hardness; D046911:Macromolecular Substances / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011506:Proteins / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D003102:Colloids; D046911:Macromolecular Substances; D011506:Proteins; D012996:Solutions