DEVELOPMENT AND APPLICATIONS OF MULTIFREQUENCY IMAGING AND SPECTROSCOPY METHODS IN DYNAMIC ATOMIC FORCE MICROSCOPY

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dc.contributor.advisorSolares, Santiago Den_US
dc.contributor.authorChawla, Gauraven_US
dc.contributor.departmentMechanical Engineeringen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2011-10-08T05:34:48Z
dc.date.available2011-10-08T05:34:48Z
dc.date.issued2011en_US
dc.description.abstractForce spectroscopy and surface dissipation mapping are two of the most important applications of dynamic atomic force microscopy (AFM), in addition to topographical imaging. These measurements are commonly performed using the conventional amplitude-modulation and frequency-modulation dynamic imaging modes. However, the acquisition of the tip-sample interaction force curves using these methods can generally be performed only at selected horizontal positions on the sample, which means that a 3-dimensional representation of the tip-sample forces requires fine-grid scanning of a volume above the surface, making the process lengthy and prone to instrument drift. This dissertation contains the development of two novel atomic force spectroscopy methods that could enable acquisition of 3-dimensional tip-sample force representations through a single 2-dimensional scan of the surface. The force curve reconstruction approach in the first method is based on 3-pass scanning of the surface using the recently proposed single-frequency imaging mode called frequency and force modulation AFM. A second, more versatile method based on bimodal AFM operation is introduced, wherein the fundamental eigenmode of the cantilever is excited to perform the topographical scan and a simultaneously excited higher eigenmode is used to perform force spectroscopy. The dissertation further presents the development of a trimodal AFM characterization method for ambient air operation, wherein three eigenmodes of the cantilever are simultaneously excited with the objective of rapidly and quantitatively mapping the variations in conservative and dissipative surface properties. The new methods have been evaluated within numerical simulations using a multiscale simulation methodology, and experimental implementation has been accomplished for two multifrequency variants that can provide 2-dimensional surface property contrast.en_US
dc.identifier.urihttp://hdl.handle.net/1903/11877
dc.subject.pqcontrolledMechanical engineeringen_US
dc.subject.pqcontrolledNanotechnologyen_US
dc.subject.pquncontrolledAtomic Force Microscopyen_US
dc.subject.pquncontrolledAtomic Force Spectroscopyen_US
dc.subject.pquncontrolledBimodal AFMen_US
dc.subject.pquncontrolledDual-frequency AFMen_US
dc.subject.pquncontrolledMultifrequency AFMen_US
dc.subject.pquncontrolledTrimodal AFMen_US
dc.titleDEVELOPMENT AND APPLICATIONS OF MULTIFREQUENCY IMAGING AND SPECTROSCOPY METHODS IN DYNAMIC ATOMIC FORCE MICROSCOPYen_US
dc.typeDissertationen_US

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