CAREER: Additively Manufactured Nanomaterial Layers with Submicron Structures

增材制造或3D打印是将材料连接起来以从3D模型数据制造物体的过程，通常是层层叠加，而不是具有减材特征和更长交货时间的传统制造技术。作为一项革命性的技术，增材制造显著改善了物流，快速实现了新产品并提高了材料准备程度，这对于将制造业带回美国至关重要。例如，源于大多数3D打印原理的一个显著困难是精确控制结构顺序（例如，图案化的点、线、柱）当以小规模制造多种材料时（例如，半导体工业中的纳米制造）。该学院早期职业发展（CAREER）奖将支持开发一种新的增材制造方法所需的研究，该方法可以精确处理各种材料。新的制造平台将能够在所需位置使用可选的聚合物或纳米颗粒逐层沉积纳米材料。多学科研究包括聚合物科学，纳米粒子合成和界面工程的研究。因此，新启用的复合材料可以在传感器，执行器，软机器人，超级电容器，电池和再生医学中有广泛的应用。通过让女性和代表性不足的少数民族学生参与教学，研究和国际合作，该项目将提高他们的教育和他们在重要劳动力中的代表性。目前的3D打印方法严重依赖外部领域（例如，电、磁和声辅助）以将纳米颗粒精确地放置在期望的位置并控制它们的长程有序。然而，这些3D打印平台要求纳米颗粒具有场交互性，并且当高度浓缩的纳米颗粒在胶体中形成团聚体时，它们具有制造限制。这项研究将推进一种新的3D打印方法--多相直接墨水书写（MDIW）的基础知识，以提高增材制造的精度和效率。MDIW将使亚微米级结构的沉积成为可能，而不受纳米级增材制造中通常存在的零件尺寸和构建速度的限制。此外，这项研究还涉及研究聚合物科学和纳米粒子工程的基础知识，以产生关于定向纳米粒子组装的3D打印方法的新知识。具体来说，研究小组将开发一种具有分层能力的新纳米制造机制，合成具有受控尺寸和所需表面特征的纳米颗粒，并通过操纵聚合物-纳米颗粒相互作用形成具有所需轮廓的图案化表面，以创建亚微米层次结构。在纳米复合材料中产生的异质微结构将具有理想的纳米颗粒分布和取向，并具有可控的堆积密度，从而能够演示快速原型化的多功能传感器。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。

Additive manufacturing, or 3D printing, is the process of joining materials to make objects from 3D model data, usually layer upon layer, instead of conventional manufacturing technologies with subtractive features and a longer lead time. As a revolutionary technology, additive manufacturing significantly improves logistics, quickly enables new products and increases material readiness, critical to bringing manufacturing back to the U.S. However, there are many challenges to 3D printing. For example, one significant difficulty stemming from most 3D printing principles is precisely controlling structural orders (e.g., patterned dots, lines, pillars) when manufacturing multiple materials at small scales (e.g., nanomanufacturing in the semiconductor industry). This Faculty Early Career Development (CAREER) award will support the research needed to develop a new additive manufacturing method that can precisely process a diversity of materials. The new manufacturing platform will enable layer-by-layer nanomaterial deposition at desired locations with optional polymers or nanoparticles. The multidisciplinary study includes research in polymer science, nanoparticle synthesis, and interfacial engineering. As a result, the newly-enabled composites could have broad applications in sensors, actuators, soft robotics, supercapacitors, batteries, and regenerative medicine. By involving female and underrepresented minority students in teaching, research, and international collaborations, this project will enhance their education and their representation in an important workforce.Current 3D printing methods rely heavily on external fields (e.g., electrical, magnetic, and acoustic assistance) to precisely place nanoparticles at desired locations and control their long-range orders. However, these 3D printing platforms mandate nanoparticles to be field-interactive, and they have manufacturing limitations when highly concentrated nanoparticles form agglomerations in colloids. This research will advance fundamental knowledge of a new 3D printing method, Multiphase Direct Ink Writing (MDIW), to improve additive manufacturing precision and efficiency. MDIW will enable the deposition of submicron-scale structures without the constraints on part size and build speeds that are typically present in nanoscale additive manufacturing. In addition, this research involves studying the fundamentals of polymer science and nanoparticle engineering to generate new knowledge concerning a 3D printing method for directed nanoparticle assembly. Specifically, the research team will develop a new nanomanufacturing mechanism with layering capabilities, synthesize nanoparticles of controlled dimensions and with desired surface features, and form patterned surfaces with desired profiles by manipulating polymer-nanoparticle interactions to create submicron hierarchical structures. The heterogeneous microstructures generated in the nanocomposites will possess desirable nanoparticle distributions and orientations with controlled packing density, enabling the demonstration of rapidly-prototyped multifunctional sensors.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.