Fabrication of Three-Dimensional Microvascular Networks for Biomedical Microfluidics

这项研究的广泛目标是了解由相互连接的微通道(1-300 mm)组成的三维微血管网络的加工科学。实验方法是通过机器人控制沉积(RCD)新的逃逸有机墨水来制造这些网络。所提出的RCD路线依赖于一层又一层地沉积逃逸的纳米复合有机墨水来创建三维流体路径。这是一种无模沉积过程，其中首先形成网络的独立支架，然后渗透第二(结构)基质相并移除牺牲支架。本研究将专注于用于三维独立支架结构的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最终固化的随时间变化的过程模型。将研究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、挤出压力)对制造过程中形状演变的影响。最后，将评估在不同结构和流动条件下制作的三维微血管流体装置的混合性能。所提出的研究有望为敏捷制造微流体网络提供基础知识。三维微血管网络将为生物医学中的新一代微流控设备提供一个使能平台，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/ID等应用。在整个项目期间，将为一名在伊利诺伊大学跨学科研究小组接受教育的研究生提供培训，该小组促进跨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.