Scalable Nanomanufacturing of Optical Metasurfaces by Hierarchical Printing and Predictive Modeling

光学超表面的设计是为了瞬间引导和控制光和图像。它们可以实现从更薄、更轻的智能手机到自动驾驶汽车和工业机器人的超快速图像处理等应用。目前用于制造光学超表面的工艺缓慢且昂贵，阻碍了它们在产品中的大规模使用。本基金研究一种制造光学超表面的新工艺。这一过程被称为分级印刷的可扩展纳米制造，涉及到将特殊印章快速滚动到透明薄片上，以大规模生产纳米纹理表面，从而最大限度地减少制造浪费和成本。然后使用特殊油墨进行高速数字喷墨印刷，以修改这些超表面来操纵光线，将这些薄片变成可以执行不同功能的表面。为了使这成为现实，研究具有特殊性能的涂层，使其能够快速纳米化。该项目还研究了印刷油墨和纳米纹理表面之间的相互作用，这是该方法的关键要素。高功能超表面光子元件在平面相机、医疗诊断和光学计算等应用中的可用性极大地影响了国家的繁荣、健康和安全。该基金通过在该项目中工作的全日制研究生的外展工作，吸引在科学和工程领域未被充分代表的青年。在这项工作中，技术驱动的制造业和教育相结合，通过扩大高生产率、技术驱动的美国制造业基础和劳动力，产生了经济和社会影响。通过分层印刷工艺实现二维光学超表面的可扩展纳米制造，可以为能源、信息处理和通信领域的应用带来新的低成本、超薄光子学类别，并提供对纳米级流体和表面现象的见解，从而进一步扩大分层纳米制造的采用。这个项目的范围分为四个方面。第一个重点是开发一个预测计算模型，用于在纳米印迹表面上打印飞升液滴的润湿。其次，预测模型的结果用于指导实验研究和制造研究，以低成本的方式使用高分辨率喷墨打印可大规模制造数字修饰的二维周期性纳米结构表面。这种分层印刷通过低成本沉积局部相移修饰剂，为超表面赋予了数字可定制的光子功能。第三和第四次推力为光学元元件提供了初步设计，表征了这些分层印刷结构的特性，并提供了反馈，以指导纳米制造工艺的进一步研究和发展。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

Optical metasurfaces are designed to steer and control light and images instantaneously. They enable applications ranging from thinner, lighter smartphones to ultrafast image processing for self-driving cars and industrial robots. Processes used today to make optical metasurfaces are slow and costly, preventing their wide scale use in products. This grant investigates a new process to manufacture optical metasurfaces. The process, called scalable nanomanufacturing by hierarchical printing, involves rapidly rolling special stamps onto transparent sheets to produce nanotextured surfaces at large scale, thus minimizing manufacturing waste and cost. High speed digital inkjet printing with special inks is then used to modify these metasurfaces to manipulate light, turning the sheets into surfaces that can perform different functions. For this to become a reality, research on coatings with special properties that allow them to be rapidly nanotextured is performed. This project also studies interactions between printing ink and nanotextured surfaces, a critical element of the approach. The availability of highly functional metasurface photonic elements for applications such as planar cameras, medical diagnostics and optical computing greatly impacts the nation's prosperity, health and security. This grant engages underrepresented youth in science and engineering through the outreach work of full-time graduate students working on this project. The combination of technology-driven manufacturing and education in this work makes economic and societal impact by expanding a high productivity, technology-driven US manufacturing base and workforce.Scalable nanomanufacturing of 2D optical metasurfaces by a hierarchical printing process could lead to new classes of low cost, ultrathin, photonics for applications in energy, information processing, and communication as well as provide insights into nanoscale fluid and surface phenomena which can expand the further adoption of hierarchical nanomanufacuring. This project's scope is broken down into four areas. The first thrust is to develop a predictive computational model for the wetting of femtoliter printed droplets on nanoimprinted surfaces. Secondly, the results from the predictive model are used to guide experimental studies and manufacturing research towards scalably fabricating digitally-modified 2D periodic nanostructure surfaces in an inexpensive process that uses high-resolution inkjet printing. This hierarchical printing imparts digitally-customizable photonic functions to the metasurfaces by depositing localized phase shift modifiers at low-cost. The third and fourth thrusts provide initial designs for the optical meta-elements, characterize the properties of these hierarchically printed structures and provide feedback to guide further study and development of the nanomanufacturing process.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.