Collaborative Research: Variothermal Roll-to-Roll Embossing Process for Rapid and Precision Production of Large-Area Microstructures

这个合作研究项目的目的是确定在大面积聚合物薄膜上制造微结构的连续压印过程是否可以实现可接受的复制保真度。该方法是用具有改变辊表面温度能力的压花辊来压花聚合物薄膜。这种温度在轧辊周长上的空间变化将通过一种创新的高频加热方法来实现，这种加热方法可以实现超过每秒100摄氏度的温度变化速率。实验将观察快速加热聚合物薄膜的可行性及其对聚合物变形行为的影响。此外，在实验验证的基础上，建立了这种创新聚合物微加工工艺的预测数学模型。如果成功，这项研究将导致一种新的制造工艺，用于在聚合物薄膜上制造微结构。基本的贡献是预期的建模和材料行为的聚合物变形在压花为基础的过程。具体来说，该研究将促进对非晶聚合物在急剧温度梯度下的变形的理解，以及这种中观行为对压花过程中流动模式发展的影响。此外，这种新的制造方法有望在质量和成本效益方面发挥重要作用，以精确的尺寸，高纵横比，锋利的半径和脆脆的边缘制造微结构。这一过程将进一步有利于传统的薄膜纹理工业，在开发与地形相关的表面功能的新应用方面，这是以前无法实现的。此外，该项目的跨学科性质将拓宽研究生和本科生的教育和培训。预计该项目的成果将丰富更广泛的课程开发工作，特别是在聚合物加工、计量和微/纳米技术领域。

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.