CAREER: Additive Manufacturing with Acoustically Assembled Multi-Scale Composite Materials

这项教师早期职业发展（Career）资助的重点是理解和推进下一代功能材料增材制造的新加工途径。增材制造技术在追求几何复杂性、可扩展性和可重复性方面迅速成熟；然而，在定制的、特定应用的工程材料方面，类似的进展是有限的。在微结构和组件水平上控制印刷结构的创新使先进的多功能、多材料复合材料得以实现。这种能力对于满足高容量储能、清洁能源和量子计算等变革性技术对材料的苛刻要求至关重要。该研究项目旨在开发、理解和验证外场（如声场）在增材制造过程中的应用，并发现能够对微粒子和纳米粒子成分进行精确空间控制的基本过程机制。本研究的跨学科性质扩大了跨学科培训的机会，并将该项目定位为提高K-12学生对科学、技术、工程、艺术和数学（STEAM）的兴趣。该项目建立了与研究成果直接结合的教育和推广活动，包括：(i)年度增材制造制造马拉松，重点关注创新的分布式制造技术；（ii）基于文化的工程推广计划，向夏威夷土著学生推广STEAM职业；（iii）指导研究机会，支持STEAM教育和劳动力发展；以及（iv）本科和研究生水平的课程创新。本研究的具体目标是发现增材制造声学组装多尺度复合材料的科学基础，这些材料具有由确定性有序微结构产生的工程性能。制造纳米颗粒基复合材料的核心挑战是控制纳米颗粒在多个长度尺度上的空间分布。外场，如声场，已经被证明可以在直接沉积增材制造过程中对微尺度颗粒进行空间控制。该研究项目提出了一种声学增材制造方法，该方法结合了三种机制，使块状材料的连续分层组装成为可能：(i)表面功能化，在溶液中产生有序/无序的微米级纳米颗粒聚集体；（ii）声场，将微尺度聚集体组装成中尺度结构；（iii）将这些中尺度结构直接沉积成块状部件。该项目结合了理论和实验研究，系统地调查和揭示了基于流动的、现场辅助增材制造在多个长度尺度上的基本原理。一个关键的焦点是更好地理解控制声场使用的加工-结构-性能关系，以制造具有特定功能梯度特性的多尺度复合材料。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。

This Faculty Early Career Development (CAREER) grant focuses on understanding and advancing a new processing pathway for the additive manufacturing of the next-generation functional materials. Additive manufacturing technologies have rapidly matured in pursuit of geometric complexity, scalability, and reproducibility; however, similar advances in customized, application-specific engineered materials are limited. Innovations to control printed architectures across both microstructural and component levels enable the realization of advanced multi-functional, multi-material composites. Such capabilities are critical to addressing the demanding material requirements of transformative technologies including high-capacity energy storage, clean energy, and quantum computing. This research project seeks to develop, understand, and validate the application of external fields, such as acoustic fields, within additive manufacturing processes and discover the fundamental process mechanisms that enable precise spatial control over micro- and nanoparticle constituents. The cross-disciplinary nature of this research expands opportunities for interdisciplinary training and positions this project for enhancing interest K-12 students in science, technology, engineering, arts, and mathematics (STEAM). This project establishes education and outreach activities directly integrated with research outcomes including: (i) an annual Additive Manufacturing Make-a-thon focused on innovative distributed manufacturing technologies, (ii) a culture-based engineering outreach program to promote careers in STEAM to Native Hawaiian students, (iii) mentored research opportunities to support STEAM education and workforce development, and (iv) curriculum innovation at the undergraduate and graduate levels. The specific goal of this research is to discover the scientific foundations for the additive manufacturing of acoustically assembled multi-scale composite materials with engineered properties resulting from deterministically ordered microstructures. A central challenge to creating nanoparticle-based composite materials is the control of the spatial distribution of nanoparticles across multiple length-scales. External fields, such as acoustic fields, have been shown to enable spatial control over microscale particles during a direct deposition additive manufacturing process. The research project proposes an acoustophoretic additive manufacturing method that combines three mechanisms to enable the continuous hierarchical assembly of bulk materials: (i) surface functionalization to create ordered/disordered micron-scale nanoparticle aggregates in solution, (ii) acoustic fields to assemble microscale aggregates into mesoscale structures, and (iii) direct deposition of these mesoscale structures into bulk components. The project combines theoretical and experimental studies to systematically investigate and reveal the fundamental principles governing the mechanics of flow-based, field-assisted additive manufacturing across multiple length scales. A key focus is to obtain a better understanding of the processing-structure-property relationships governing the use of acoustic fields to fabricate multiscale composite materials with specific, functionally-graded properties.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.