The proposed thesis aims to investigate the physics underlying polymer deformation during thermomechanical manufacturing of polymer microstructures and nanostructures. The research seeks to impact fabrication of integrated circuits, microelectromechanical systems, and flexible electronics and inform processes for high density data storage. The research focuses on polymer flow during embossing and polymer deformation at length scales near the polymer coil radius. The first thrust studies polymer flow in microembossing and nanoimprint lithography (NIL) to establish rational process design rules for NIL. Experiments and simulations investigate polymer filling cavities with feature sizes 100 nm 100 μm. Global flow analysis examines polymer flow between large areas of wafer-scale molds. The second thrust seeks to understand polymer flows in high resolution nanoimprint and atomic force microscope (AFM) nanoindentation where features are of similar size to polymer coils. Modified continuum simulations model the response of high molecular weight polymer thin films to rapid indentation of AFM probes. Experiments investigate polymer flow during nanoembossing confined to geometries of width less than the polymer coil radius. This work investigates polymer flow at all length scales relevant to thermomechanical processing, from local polymer interactions in confined geometries to large field material displacement in wafer-scale embossing.