Collaborative Research: A Novel Control Strategy for 3D Printing of Micro-Scale Devices

增材制造系统，通常称为3D打印机，准备在许多中型应用（尺寸从1毫米到100毫米的零件）中取代传统制造操作。同样，微尺度（尺寸从0.001到0.1毫米）的3D打印有可能彻底改变生物和化学传感器以及集成电路的原型和制造方式。3D打印机通过一次沉积一层薄薄的材料来构建复杂的部件。电流体动力学喷射或电子喷射印刷是这种工艺的一种有前途的微尺度版本。该项目将为标准的电子喷墨打印机添加传感器，并应用创新的控制律，以大大提高最终零件的精度。控制律是基于这样的观察，即3D打印的特征通常从一层到下一层变化很小。通过观察一个层如何偏离其期望的形状，可以修改基线电子喷射控制以提高下一层的精度。在这个项目中，原子力显微镜将与电子喷射打印机集成，以测量每层的形状。为了更好地校正印刷过程，还将测量每层周围的电场。该技术研究计划与教育推广相结合，旨在发起本科生“微型制造者”俱乐部，并促进基于定制微电路和传感器的廉价喷墨打印的开源、自下而上的运动。微尺度增材制造，特别是电流体动力学喷射打印，有可能彻底改变3D、功能性、微尺度设备制造。限制制造能力的这种阶跃变化的是微尺度增材制造系统对过程监测、调节和质量控制范例的依赖，该过程监测、调节和质量控制范例是在过程后以特定方式执行的。这项研究将通过在两个领域产生基础科学知识来打破这种开环范式：1）控制理论框架的合成，以利用鲁棒且计算高效的基于学习的算法来补偿空间干扰，以及2）利用第一原理物理模型研究电流体动力学喷射印刷中材料的带电射流与基底之间的相互作用，并通过利用电流体动力学喷射打印和原子力显微镜的新集成。这项研究将有助于将3D微尺度增材制造从一个新生的，开环和特设的技术集转变为一个完全自动化，准确和强大的闭环系统所需的基础知识。

Additive manufacturing systems, often called 3D printers, are poised to displace conventional manufacturing operations in many meso-scale applications (parts from 1 to 100 millimeters in size). Similarly, 3D printing at the micro-scale (from 0.001 to 0.1 millimeters in size) has the potential to revolutionize the way that biological and chemical sensors and integrated circuits are prototyped and manufactured. 3D printers build up complex parts by depositing one thin layer of material at a time. Electrohydrodynamic jet, or e-jet, printing is a promising micro-scale version of this process. This project will add sensors to a standard e-jet printer, and apply an innovative control law to greatly improve the precision of the resulting parts. The control law is based on the observation that 3D printed features typically change very little from one layer to the next. By observing how a layer deviates from its desired shape, the baseline e-jet control can be modified to improve the accuracy of the next layer. In this project, an atomic force microscope will be integrated with an e-jet printer to measure the shape of each layer. To better correct the printing process, the electric field around each layer will also be measured. The technical research plan is integrated with educational outreach to initiate undergraduate "micro-maker" clubs and catalyze an open-source, bottom-up movement based on inexpensive ink-jet printing of custom microcircuits and sensors.Micro-scale Additive Manufacturing, and in particular, electrohydrodynamic jet printing, has the potential to revolutionize 3D, functional, micro-scale device fabrication. Limiting this step change in manufacturing capabilities is the reliance of micro-scale Additive Manufacturing systems on a process monitoring, regulation, and quality control paradigm that is performed post-process and in an ad hoc manner. This research will break this open-loop paradigm by generating fundamental scientific knowledge in two areas: 1) the synthesis of a controls theoretic framework to compensate for spatial disturbances with a robust and computationally efficient learning-based algorithm and 2) the study of interactions between charged jets of materials and substrates in electrohydrodynamic jet printing using first principles physics models and validated by empirical studies leveraging a novel integration of electrohydrodynamic jet printing and atomic force microscopy. This research will contribute the fundamental knowledge required to transform 3D micro-scale Additive Manufacturing from a nascent, open-loop and ad hoc technology set to a fully automated, accurate, and robust closed-loop system.