CAREER: Graded and Reliable Aerosol Deposition for Electronics (GRADE): Understanding Multi-Material Aerosol Jet Printing with In-Line Mixing

计算机控制的打印技术可以制造精密而复杂的部件。当这些方法被用于打印电子材料时，它们可以生产传感器和电路等设备。打印包含材料成分和性能梯度的部件的动机很强烈，这些部件可以模拟生物材料，改善机械接口，并实现先进的电子功能。该学院早期职业发展计划(CALEAR)奖支持基础研究，以了解和控制多材料气雾剂喷墨打印，这是一种非常适合制造用于电子设备的此类材料梯度的技术。这种印刷方法可以在沉积过程中混合不同油墨的微滴来改变材料的组成，并在三维上协调这种材料变化与图案化。这项技术与航空航天、生物医学、汽车、能源和国防应用相关，从而促进了国家繁荣和安全。此外，该研究在制造、气溶胶和流体动力学以及材料科学方面追求基础性进展，从而推动了科学的进步。除了这项研究的核心研究目标外，还将建立一个外展计划，通过互动数字打印活动，让4-5年级的学生接触科学和工程概念，并将基于游戏和项目的学习纳入本科制造工程课程，以改善劳动力发展。本项目的目标是建立多材料喷雾打印的机理知识和控制，以实现材料梯度的图案化。不同的材料将混合在打印头内的气雾剂相中，允许数字控制混合比例。将通过实验、模拟和理论相结合的方法，评估气溶胶、液体和胶体相的混合机制，以了解材料化学、油墨配方、气溶胶物理和打印参数对混合效率、均匀性和控制的影响。在材料组成和性能中制造自定义梯度的能力将促进在混合电子学的背景下对功能梯度材料的材料-加工-结构-性能关系的广泛研究，包括电磁器件、电化学、界面力学和仿生结构。为了指导这一能力的发展，该项目将寻求垂直分级的接口以减少热膨胀失配造成的故障，以及横向分级的导体以支持生物兼容电路。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。

Computer-controlled printing technologies allow manufacturing of precise and complex parts. When these methods are used to print electronic materials, they can produce devices such as sensors and circuits. There is a strong motivation to print parts that contain gradients in material composition and properties, which can mimic biological materials, improve mechanical interfaces, and enable advanced electronic functionality. This Faculty Early Career Development Program (CAREER) award supports fundamental research to understand and control multi-material aerosol jet printing, a technology well suited for manufacturing such material gradients for electronic devices. This printing method can mix micro-scale droplets of different inks during the deposition process to change the material composition, and coordinate this material change with patterning in three dimensions. This technology is relevant to aerospace, biomedical, automotive, energy, and defense applications, thus promoting national prosperity and security. Moreover, the research pursues fundamental advances in manufacturing, aerosol and fluid dynamics, and materials science, thus advancing the progress of science. Alongside the core research objectives of this research, an outreach program will be established to engage 4th-5th grade students with science and engineering concepts via interactive digital printing activities, and game- and project-based learning will be incorporated in undergraduate manufacturing engineering coursework to improve workforce development. The goal of this project is to establish mechanistic knowledge and control of multi-material aerosol jet printing for patterning material gradients. Different materials will be mixed in the aerosol phase within the printhead, allowing digital control of the mixing ratio. Mixing mechanisms for the aerosol, liquid, and colloid phases will be evaluated to understand the effects of materials chemistry, ink formulation, aerosol physics, and print parameters on the mixing efficacy, uniformity, and control using a combination of experiments, simulation, and theory. The ability to fabricate custom gradients in material composition and properties will stimulate broad research of material-processing-structure-property relationships for functionally graded materials in the context of hybrid electronics, including electromagnetic devices, electrochemistry, interfacial mechanics, and biomimetic structures. To guide development of this capability, this project will pursue vertically graded interfaces to reduce failure from thermal expansion mismatch, along with laterally graded conductors to support biocompatible circuits.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.