CAREER: Intensifying multi-material additive manufacturing using advective assembly

多材料增材制造在单个3d打印对象中包含多个物种，以增强其机械性能和功能。这项技术可以加强当地制造业的努力，提高供应链的弹性。然而，传统的逐层构建方法必须在低体积吞吐量下运行，以保持良好的特征分辨率，从而限制了在给定时间内可以产生的对象数量。为了克服这一挑战，该项目将设计、制造和测试模块化3D打印喷嘴，以便在沉积前快速构建多材料复合材料。实现更快、更高分辨率的多材料打印将为多个领域的产品开发和制造开辟新的途径，包括医疗保健、电子设备制造和食品加工。建立本地制造业基础设施需要一个专门的用户社区，就像它需要新技术一样。因此，这个奖项的一个协同目标是让工程学生成为科学大使，并在更广泛的社区开展外展活动。所提出的研究将阐明平流组合喷嘴所能获得的最大增益。平流装配器将添加、切割和旋转连接组合在特定的序列中，以增强混乱的平流和对齐、乘法和收缩共流流线。模块化流体装置可以挤出精细的分层结构（例如，树突树和交叉电极），可以为特定的增材制造应用量身定制。然而，目前还不清楚当扭曲的几何形状在高流速下运行时，结构是如何扭曲的。该奖项将使用实验和计算工具系统地研究建筑保真度作为三类独立变量的函数：器件几何形状、油墨流变性和体积吞吐量。结果将阐明工作中的基本机制，可以实现的架构，可以处理的油墨，以及使用平流组装可以实现的潜在吞吐量。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。

Multi-material additive manufacturing incorporates multiple species within a single 3D-printed object to enhance its mechanical properties and functionality. This technology could bolster local manufacturing efforts and improve the resilience of supply chains. However, conventional layer-by-layer construction methods must operate at low volumetric throughputs to maintain fine feature resolution, limiting the number of objects that can be produced in a given time. To overcome this challenge, this project will design, fabricate, and test modular 3D printing nozzles engineered to structure multi-material composites rapidly before deposition. Achieving faster multi-material printing with higher resolution will open new avenues to product development and manufacturing in several sectors, including health care, electronic device fabrication, and food processing. Building local manufacturing infrastructure requires a dedicated user community as much as it requires new technologies. As such, a synergistic aim of this award is to empower engineering students to serve as science ambassadors and conduct outreach in the broader community. The proposed research will elucidate the maximal gains that can be achieved by advective assembly nozzles. Advective assemblers combine add, cut, and rotation junctions in particular sequences to enhance chaotic advection and align, multiply, and shrink co-flowing streamlines. The modular fluidic devices can extrude fine hierarchical architectures (e.g., dendritic trees and interdigitated electrodes) that can be tailored for specific additive manufacturing applications. However, it is unclear how architectures distort when the tortuous geometries are operated at high flow rates. This award will use experimental and computational tools to systematically study architecture fidelity as a function of three classes of independent variables: device geometry, ink rheology, and volumetric throughput. The results will elucidate the fundamental mechanics at work, the architectures that can be realized, the inks that can be processed, and the potential throughputs that can be achieved using advective assembly.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.