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

这一合作研究项目的目标是确定是否可以在可接受的复制保真度下实现连续压花工艺，以在大面积聚合物薄膜上制造微结构。该方法是用具有改变辊表面温度的能力的压纹辊来压印聚合物膜。这种轧辊周围温度的空间变化将使用一种创新的高频加热方法来实现，使用这种方法，温度变化速度可以达到每秒100摄氏度以上。通过实验观察聚合物薄膜快速加热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，将建立这一创新的聚合物微加工过程的预测数学模型。如果成功，这项研究将带来一种在聚合物薄膜上制造微结构的新工艺。期望在基于压花的工艺中聚合物变形的建模和材料行为方面做出基本贡献。具体地说，这项研究将促进对具有尖锐温度梯度的非晶态聚合物的变形以及这种介观行为对模压过程中流型发展的影响的理解。此外，这种新的制造方法有望在高质量和低成本制造具有精确尺寸、高纵横比、尖锐半径和边缘脆的微结构方面发挥重要作用。这一过程将进一步有利于传统的薄膜织构行业开发具有以前无法实现的与地形相关的表面功能的新型应用。此外，该项目的跨学科性质将扩大对研究生和本科生的教育和培训。预计该项目的结果将丰富更广泛的课程开发努力，特别是在聚合物加工、计量学和微/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.