The objective of this collaborative research project is to determine if a continuous embossing process for fabrication of microstructures on large-area polymer films can be achieved with acceptable replication fidelity. The approach is to emboss the polymer film with an embossing roll that has an ability of varying the roll surface temperature. This spatial variation of temperature over the roll circumference will be accomplished using an innovative high-frequency heating method, with which a rate of temperature change exceeding 100C per second can be achieved. Experiments will be conducted to observe the feasibility of the rapid heating on polymer films and its effect on the deformation behavior of polymers. Further, a predictive mathematical model for this innovative polymer microfabrication process will be established based on the experimental verifications. If successful, this research will lead to a new manufacturing process for fabricating microstructures on polymeric films. Fundamental contributions are anticipated regarding the modeling and material behavior of polymer deformation in embossing based processes. Specifically, the research will advance understanding of deformation of amorphous polymers with sharp temperature gradient and the influence of such meso-state behavior on the development of the flow pattern during the embossing processes. Moreover, this new manufacturing method is expected to play a vital role in terms of quality and cost-effective fabrication of microstructures with accurate dimensions, high aspect ratios, sharp radii, and crispy edges. The process would further benefit the traditional film texturing industry in the development of novel applications with topography-related surface functionalities that cannot be realized before. In addition, the interdisciplinary nature of the project will broaden the education and training of graduate and undergraduate students. It is expected that the results of the project will enrich broader curriculum development efforts, particularly in the areas of polymer processing, metrology, and micro/nano technology.
