CAREER: Integrated Approach to Modeling, Simulation, and Design for Manufacture of Micro-hot Embossing Using a Polymer Glass Transition Modeling Framework

这个教师早期职业发展（CAREER）计划项目的研究目标是开发实验和数值工具，以优化非晶聚合物的微热压工艺。 热压印用于赋予聚合物表面微观特征，在光学、电子、汽车和生物医学工业中非常重要。 该研究将包括对加工过程中表面特性影响的实验研究，其结果将用于开发和验证新的热压成型有限元模拟。 热压是在玻璃化转变温度附近发生的许多过程之一。目前在此温度范围内的实验数据和本构模型是有限的，限制了昂贵的迭代方法的热压设计。 本研究旨在通过玻璃化转变温度附近的材料表征和建模、工艺级有限元建模和实验室规模的压花实验来满足这些需求。教育目标是将这项研究融入现有的工程课程，并开发推广方法，以提高8年级学生的技术意识和对工程的兴趣。如果成功，这项研究的结果将通过以下方式推动聚合物制造的最新技术：（1）产生玻璃化转变附近聚合物的新实验数据，玻璃化转变是工业上重要的温度范围，但公布的数据有限;（2）开发一种新的本构模型，以捕获在整个玻璃化转变的宽温度范围内的热塑性行为;（3）提供用于微热压印的设计和优化的计算建模工具;以及（4）提供对微尺度表面特征在热压印中的作用的实验见解。 热压印是一种环保的替代创造表面特征和开发的设计工具，将促进推动向纳米级的功能。 通过该奖项的研究和教育的整合将通过嵌入本科有限元和研究生聚合物加工课程的项目提供对前沿研究的切实接触。

The research objective of this Faculty Early Career Development (CAREER) Program project is to develop experimental and numerical tools to optimize the micro-hot embossing process for amorphous polymers. Hot embossing is used to impart micro-scale features to polymer surfaces and is important in the optical, electronics, automotive, and biomedical industries. The research will include an experimental investigation of the effects of surface characteristics in processing, and the results will be used to develop and validate new finite element simulations of hot embossing. Hot embossing is one of many processes that take place near the glass transition temperature. Current experimental data and constitutive models in this temperature range are limited, restricting the design of hot embossing to costly iterative approaches. This research aims to address these needs through material characterization and modeling near the glass transition temperature, process-level finite element modeling, and lab-scale embossing experiments for model validation. The educational objective is to integrate the research into existing engineering courses and to develop outreach methods to promote technical awareness and interest in engineering among 8th grade students.If successful, the results of this research will advance the state of the art in polymer manufacturing by (1) generating new experimental data for polymers near the glass transition, an industrially important temperature range with limited published data; (2) developing a new constitutive model to capture thermoplastic behavior over a wide range of temperatures across the glass transition; (3) providing computational modeling tools for design and optimization of micro-hot embossing; and (4) providing experimental insight into the role of micro-scale surface features in hot embossing. Hot embossing is an environmentally-friendly alternative for creating surface features and the developed design tools will facilitate the push toward nano-scale features. The integration of research and education through this award will provide tangible exposure to cutting-edge research through projects imbedded in undergraduate finite element and graduate polymer processing courses.