CAREER: 3D Printing of Multiscale, Multifunctional Porous Structures by Selectively Freezing Multidimensional Nanomaterials

多尺度、多功能的多孔结构存在于自然界中，并在许多工程应用中使用。然而，已经证明使用传统的制造技术制造这样的结构是极其困难的，部分原因是它们的复杂结构需要在许多长度尺度上开发。为了应对这一挑战，该学院早期职业发展（CAREER）计划项目将通过选择性冷冻和原位冰模板纳米材料来制造多尺度，多功能多孔结构，研究冷冻纳米打印（FNP）方法。结合实验和建模的方法将被用来理解FNP的基本机制，并阐明参数-过程-结构-性质的关系。该研究将有助于3D打印过程，可以从根本上解锁结构和功能特性，并导致能源，健康，环境，航空航天，汽车和消费品等领域的工业应用。 因此，该项目对经济福利、国家健康和安全产生了积极影响。教育目标是激励高中生，吸引大一本科生到该领域，培养研究生，并通过实践教育和基于3D打印技术的制造创新向公众提供服务。活动包括发布开源3D打印系统;开发网络访问讲座;组织TINKER营地研讨会，自由伙伴关系计划和3D打印研讨会。这个职业项目将专注于冷冻纳米打印（FNP）技术，以制造多尺度和多功能的多孔结构。其核心前提是，微观结构可以通过原位冰模板来操纵，而宏观结构可以通过喷墨打印来控制。如果成功，该项目将显著推进对FNP过程中复杂现象的科学理解，包括1）理解高纵横比多维纳米材料如何与打印喷嘴相互作用，以及油墨成分和工艺参数如何影响液滴形成，并最终影响所产生的宏观结构的性质，2）阐明了多维纳米材料在液滴式冰模板过程中与冰晶相互作用的机理，以及这种复杂行为对微结构性能的影响，3）研究了工艺参数与复合材料界面结构的关系，以及界面结构对复合材料多功能性的影响。通过实践为基础的教育活动，该项目将提供令人兴奋的课程材料和实验室项目，从K-12到研究生水平的学生。向大学预科机构提供与学生日常生活相关的课程将扩大少数族裔和代表性不足群体的参与。通过教学和研究为本科生和研究生量身定制的课程将激发他们对科学和工程的终身兴趣。该奖项反映了NSF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。

Multiscale, multifunctional porous structures are found in nature and used in many engineering applications. However, it has proven extremely difficult to fabricate such structures using traditional manufacturing techniques, partially because their intricate structures need to be developed over many length scales. To address this challenge, this Faculty Early Career Development (CAREER) Program project will investigate a freeze nano printing (FNP) approach through selectively freezing and in situ ice-templating of nanomaterials to fabricate multiscale, multifunctional porous structures. A combined experimental and modeling methodology will be used to understand the fundamental mechanism in FNP and elucidate the parameter-process-structure-property relations. The research will contribute a 3D printing process that can fundamentally unlock structural and functional properties and lead to industrial applications in areas such as energy, health, environment, aerospace, automotive, and consumer products. As such, the project positively impacts economic welfare, national health and security. The educational objective is to inspire high school students, attract freshman-level undergraduate students to the field, train graduate students, and provide outreach to the general public through hands-on education and manufacturing innovation based on 3D printing technologies. Activities include publishing an open-source 3D printing system; development of web-accessible lectures; and organization of a TINKER camp workshop, a Liberty Partnerships program, and a 3D printing symposium. This CAREER project will focus on freeze nano printing (FNP) technology to fabricate multiscale and multifunctional porous structures. The central premise is that the microscale structure can be manipulated by in situ ice-templating, while the macroscale structure can be controlled by inkjet printing. If successful, this project will significantly advance scientific understanding of the complex phenomena in FNP process, including 1) understanding how the high-aspect-ratio multidimensional nanomaterials interact with printing nozzle, and how the ink composition and process parameters affect the drop formation, and ultimately influence the property of the produced macrostructure, 2) elucidating the mechanism of how the multidimensional nanomaterials interact with ice-crystals during the droplet-wise ice-templating process, and how the complex behavior affects the microstructural property, and 3) studying the relation between the process parameters and the interfacial structures of the multiple materials, and how the interfacial structures influence the multifunctionality. Through hands-on-based educational activities, this project will provide exciting course materials and lab projects to students from K-12 to graduate-level. Outreach to pre-college institutes with curriculum relevant to students' daily lives will broaden participation of the minority and underrepresented groups. Curriculum tailored to the undergraduate and graduate students through teaching and research will inspire their lifelong interest in science and engineering. Community outreach will help promote awareness and adoption of 3D printing technologies and democratize advanced manufacturing.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.