CAREER: Additively Manufactured Nanomaterial Layers with Submicron Structures

加法制造或3D打印是将材料连接在一起，根据3D模型数据制造对象的过程，通常是逐层进行的，而不是具有减法特征和较长交货期的传统制造技术。作为一项革命性的技术，加法制造显著改善了物流，快速推出了新产品，并提高了材料准备程度，这对将制造业带回美国至关重要。然而，3D打印也面临着许多挑战。例如，大多数3D打印原理产生的一个重大困难是在小规模制造多种材料(例如半导体行业中的纳米制造)时精确控制结构顺序(例如，图案化的点、线、柱)。该学院早期职业发展(CALEAR)奖将支持开发一种新的添加剂制造方法所需的研究，该方法可以精确处理各种材料。新的制造平台将使用可选的聚合物或纳米颗粒在所需位置逐层沉积纳米材料。这项多学科研究包括聚合物科学、纳米颗粒合成和界面工程方面的研究。因此，新启用的复合材料可能在传感器、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。通过让女性和少数族裔学生参与教学、研究和国际合作，该项目将加强她们的教育，并提高她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磁场(例如，电、磁和声学辅助)来精确地将纳米颗粒放置在所需位置并控制其远程顺序。然而，这些3D打印平台要求纳米颗粒必须是场交互的，并且当高浓度的纳米颗粒在胶体中形成团聚时，它们存在制造限制。这项研究将增进对一种新的3D打印方法--多相直接墨水写入(MDIW)的基础知识，以提高添加制造的精度和效率。MDIW将使亚微米级结构的沉积成为可能，而不会受到纳米级添加剂制造中通常存在的部件尺寸和制造速度的限制。此外，这项研究还包括研究聚合物科学和纳米颗粒工程的基础知识，以产生关于定向纳米颗粒组装的3D打印方法的新知识。具体地说，研究团队将开发一种具有分层能力的新纳米制造机制，合成尺寸可控、具有所需表面特征的纳米颗粒，并通过操纵聚合物-纳米颗粒相互作用来创建亚微米分层结构，形成具有所需轮廓的图案化表面。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，并控制堆积密度，从而能够展示快速原型的多功能传感器。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.