Fabrication of Three-Dimensional Microvascular Networks for Biomedical Microfluidics

本研究的主要目的是了解由相互连接的微通道（1-300毫米）组成的三维微血管网络的处理科学。实验方法是通过机器人控制沉积（RCD）的新型逸散性有机油墨来制造这些网络。提出的RCD路线依赖于一层一层沉积的易失性纳米复合有机油墨来创建三维流体路径。这是一种无模沉积过程，首先形成网络的独立式支架，然后浸润次级（结构）基质相，去除牺牲支架。本研究将重点关注用于三维独立式支架结构RCD的纳米复合有机油墨的设计和表征，以及跟踪支架网络从沉积到次级基质最终固化的时间依赖性变形的过程模型。研究了纳米复合油墨的组成和流变性，以及各种工艺参数（如喷嘴直径、沉积速度、挤压压力）对制造过程中形状演变的影响。最后，将在不同的结构和流动条件下对制备的三维微血管流体装置的混合性能进行评估。所提出的研究有望为微流体网络的敏捷制造提供所需的基础知识。三维微血管网络将为生物医学领域的新一代微流控设备提供一个有利的平台，用于基因测序、功能基因组学、药物发现、药物基因组学、诊断和病原体检测/识别等应用。在整个项目期间，将为一名研究生提供培训，该研究生在伊利诺伊大学的一个跨学科研究小组中接受教育，该小组促进了多个学科领域的互动。

The broad objective of this research is to understand the processing science of three-dimensional microvascular networks consisting of interconnected microchannels (1-300 mm). The experimental approach is to fabricate these networks by robotically controlled deposition (RCD) of new fugitive organic inks. The proposed RCD route relies on a layer-by-layer deposition of fugitive nanocomposite organic inks to create three-dimensional fluid paths. It is a mold-less deposition process in which a freestanding scaffold of the network is formed first, followed by infiltration of a secondary (structural) matrix phase and removal of the sacrificial scaffold. This research will focus on the design and characterization of nanocomposite organic inks for use in RCD of three-dimensional freestanding scaffold structures, as well as process models that track the time-dependent deformation of the scaffold network from deposition through final curing of the secondary matrix. The effects of nanocomposite ink composition and rheology as well as various process parameters (e.g., nozzle diameter, deposition speed, extrusion pressure) on shape evolution during fabrication will be studied. Finally, the mixing performance of fabricated 3-D microvascular fluidic devices will be evaluated for a variety of architectures and flow conditions.The proposed research is expected to provide fundamental knowledge needed for agile fabrication of microfluidic networks. Three-dimensional microvascular networks will provide an enabling platform for a new generation of microfluidic devices in biomedicine for applications such as gene sequencing, functional genomics, drug discovery, pharmacogenomics, diagnostics, and pathogen detection/ID. Training will be provided for one graduate student throughout the project period educated in an interdisciplinary research group at the University of Illinois that facilitates interactions across a number of disciplinary fields.