Department of Mechanical Engineering, University of Ottawa, Ottawa, Canada.
Lab Chip. 2019 Jun 11;19(12):2096-2106. doi: 10.1039/c9lc00254e.
Blood vessels in living tissues are an organized and hierarchical network of arteries, arterioles, capillaries, veinules and veins. Their sizes, lengths, shapes and connectivity are set up for an optimum perfusion of the tissues in which they deploy. In order to study the hemodynamics and hemophysics of blood flows and also to investigate artificial vasculature for organs on a chip, it is essential to reproduce most of these geometric features. Common microfluidic techniques produce channels with a uniform height and a rectangular cross section that do not capture the size hierarchy observed in vivo. This paper presents a new single-mask photolithography process using an optical diffuser to produce a backside exposure leading to microchannels with both a rounded cross section and a direct proportionality between local height and local width, allowing a one-step design of intrinsically hierarchical networks.
活组织中的血管是动脉、小动脉、毛细血管、小静脉和静脉组成的有组织和分层的网络。它们的大小、长度、形状和连通性是为了使它们所部署的组织得到最佳灌注而设定的。为了研究血流的血液动力学和血液物理学，以及研究芯片上器官的人工血管系统，重现这些几何特征是至关重要的。常见的微流控技术产生的通道具有均匀的高度和矩形的横截面，无法捕捉到体内观察到的尺寸层次结构。本文提出了一种新的单掩模光刻工艺，使用光学漫射器进行背面曝光，从而产生具有圆形横截面的微通道，局部高度和局部宽度之间存在直接的比例关系，允许一步设计内在的层次网络。
