MRI: Development of Tomographic Atomic Force Microscopy for Nanoscale Volumetric Materials Property Mapping and Machining

University Of Connecticut, Storrs CT

Investigators

Abstract

Non-Technical Description: Atomic force microscopy (AFM) has become ubiquitous for nanometer scale research in science and engineering. The 50,000 AFMs worldwide focus on measurements of surface structures and properties while minimizing unintended surface modifications. This instrument development project takes a different approach and removes materials, layer-by-layer, to sequentially reveal the underlying materials while mapping their properties. The multiple images that result are assembled to achieve tomography akin to magnetic resonance imaging or computerized tomography (CT) scans, but providing materials properties in 3 dimensions at the nanoscale. The instrument development culminates in a next generation microscope with precise location control, novel imaging analysis software, and new insight into nanoscale mechanical milling as well as sub-surface materials properties. More broadly, the project enhances the University of Connecticut's microscopy user facility, and features in annual outreach events with students and teachers. The concepts will further be disseminated through a symposium on materials tomography at a scientific conference in the US organized by the principal investigator and through possible commercialization pathways. Technical Description: Leveraging advances in local patterning with robust AFM tips, this instrument development project employs sequential property mapping and fine surface milling to expose and image materials functionality as a function of depth. The resulting nanoscale tomography, "CT-AFM," necessitates a next generation microscope and custom z-axis interferometry to maintain nanoscale position registry over hundreds of images. Thin films of piezoelectrics, photovoltaics, intermetallics, and nanocomposites serve as model systems during this instrument development, and to publish examples of the novel insight provided by this new paradigm for AFM. The primary objective is to achieve through-thickness, sub-10 nm resolution. The project also explores new image analysis approaches and advances nanoscale mechanical milling.