Collaborative Research: Nanoimprinting of High Aspect-Ratio Nanostructures in Thermoplastic Polymers Using Metallic Glass Roller Molds

该合作研究团队使用多学科方法来研究通过使用金属玻璃辊模具实现热塑性聚合物膜表面可扩展压印的可行性。具有高纵横比纳米级特征的热塑性聚合物表现出多功能特性，并且在许多应用中是高度期望的，例如太阳能电池、透明导电膜和光子晶体。使用卷对卷（R2R）纳米压印制造具有纳米级特征的这种膜已经被开发用于反应性聚合物，但是对于热塑性聚合物来说一直是一个挑战，因为它们通常是100倍以上的粘性并且需要显著更高的压印压力。因此，需要开发用于热塑性纳米压印的精确且耐用的辊模具。这个合作项目涉及两个机构，一个领导调查的设计和卷到卷的热塑性基板的高纵横比纳米结构的制造，其他直接的表征和建模的努力。这项研究的结果构成了将新的制造技术成功转移到工业的科学基础，并使能源，医疗保健，汽车和电信应用的纳米器件的经济生产成为可能。该项目进一步丰富了课程开发，特别是在纳米制造的跨学科领域，并扩大了妇女和代表性不足的群体在研究中的参与。该奖项支持基础研究，以探索一种可行的纳米制造工艺，使用机械坚固的金属玻璃辊模连续生产高保真热塑性纳米结构。金属玻璃是一类高强度金属，可以像塑料一样在其过冷液态下加工成特征尺寸低至10 nm的大尺寸几何形状。该项目涉及几项任务。(1)平面奈米结构转移至金属玻璃涂布滚筒模具曲面之研究。(2)无结晶金属玻璃辊式纳米压印的热机械加工窗口的确定。(3)利用邻近加热提高复制精度。(4)印迹纳米结构复制保真度的表征。(5)基于卷对卷纳米制造过程的数值模拟性能。基本的贡献，预计在连续纳米压印过程中的金属玻璃和热塑性聚合物的纳米级动力学。特别是，研究进展的理解（a）流变学和加工微结构的性能关系，在金属玻璃和热塑性聚合物在纳米级，（B）结晶的金属玻璃在过冷液体制度，和（c）精确控制和优化的材料？该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

This collaborative research team uses a multidisciplinary approach to investigate the feasibility of scalable imprinting of thermoplastic polymer film surfaces enabled by the use of metallic glass roller molds. Thermoplastic polymers with high aspect-ratio nanoscale features exhibit versatile properties and are highly desired in numerous applications such as solar cells, transparent conducting films and photonic crystals. Manufacturing such films with nanoscale features using roll-to-roll (R2R) nanoimprinting has been developed for reactive polymers but has been a challenge for thermoplastic polymers because they are typically over 100 times more viscous and require significantly higher imprinting pressure. Hence, there emerges a need for the development of a precise and durable roller mold for thermoplastic nanoimprinting. This collaborative project involves two institutions, one leading investigations into the design and roll-to-roll manufacture of the high aspect-ratio nanostructures in thermoplastic substrates, the other directing efforts in characterization and modeling. Results from this research forms the scientific basis for successful transfer of the novel manufacturing technology to industry and enables economic production of nanodevices for applications in energy, healthcare, automotive, and telecommunication. The project further enriches curriculum development, particularly in the interdisciplinary area of nanomanufacturing, and broadens the participation of women and underrepresented groups in research. This award supports fundamental research to explore a viable nanomanufacturing process using a mechanically robust metallic glass roller mold for continuous production of high-fidelity thermoplastic nanostructures. Metallic glasses are a class of high strength metals that can be processed like plastics in their supercooled liquid state into large-scale geometries with feature sizes down to 10 nm. The project involves several tasks. (1) Investigations into the transfer of planar nanostructures onto the curved surface of metallic glass coated roller molds. (2) Identification of the thermomechanical processing window for roller nanoimprinting of metallic glasses without crystallization. (3) Utilization of proximity heating to enhance the replication precision. (4) Characterization of the replication fidelity of the imprinted nanostructures. (5) Performance of numerical modeling of roll-to-roll based nanomanufacturing processes. Fundamental contributions are anticipated regarding the nanoscale dynamics of metallic glasses and thermoplastic polymers during continuous nanoimprinting. Particularly, the research advances the understanding of (a) rheology and processing-microstructure-property relations in metallic glasses and thermoplastic polymers at nanoscale, (b) crystallization of metallic glasses in the supercooled liquid regime, and (c) precise control and optimization of material?s thermomechanical history in nanoscale fabrication.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.