Zoupanou Sofia, Chiriacò Maria Serena, Tarantini Iolena, Ferrara Francesco
CNR NANOTEC-Institute of Nanotechnology, via per Monteroni, 73100 Lecce, Italy.
Department of Mathematics & Physics E. de Giorgi, via Arnesano, University of Salento, 73100 Lecce, Italy.
Micromachines (Basel). 2021 Jan 21;12(2):104. doi: 10.3390/mi12020104.
Micromixers are essential components in lab-on-a-chip devices, of which the low efficiency can limit many bio-application studies. Effective mixing with automation capabilities is still a crucial requirement. In this paper, we present a method to fabricate a three-dimensional (3D) poly(methyl methacrylate) (PMMA) fluidic mixer by combining computer-aided design (CAD), micromilling technology, and experimental application via manipulating fluids and nanoparticles. The entire platform consists of three microfabricated layers with a bottom reservoir-shaped microchannel, a central serpentine channel, and a through-hole for interconnection and an upper layer containing inlets and outlet. The sealing process of the three layers and the high-precision and customizable methods used for fabrication ensure the realization of the monolithic 3D architecture. This provides buried running channels able to perform passive chaotic mixing and dilution functions, thanks to a portion of the pathway in common between the reservoir and serpentine layers. The possibility to plug-and-play micropumping systems allows us to easily demonstrate the feasibility and working features of our device for tracking the mixing and dilution performances of the micromixer by using colored fluids and fluorescent nanoparticles as the proof of concept. Exploiting the good transparency of the PMMA, spatial liquid composition and better control over reaction variables are possible, and the real-time monitoring of experiments under a fluorescence microscope is also allowed. The tools shown in this paper are easily integrable in more complex lab-on-chip platforms.
微混合器是芯片实验室设备中的关键部件，其低效率会限制许多生物应用研究。具备自动化能力的有效混合仍然是一项关键要求。在本文中，我们提出了一种通过结合计算机辅助设计（CAD）、微铣削技术以及通过操纵流体和纳米颗粒进行实验应用来制造三维（3D）聚甲基丙烯酸甲酯（PMMA）流体混合器的方法。整个平台由三个微制造层组成，底层有储液器形状的微通道、中央蜿蜒通道以及用于互连的通孔，上层包含入口和出口。三层的密封过程以及用于制造的高精度和可定制方法确保了整体3D架构的实现。这提供了能够执行被动混沌混合和稀释功能的埋入式运行通道，这得益于储液器层和蜿蜒层之间部分共用的路径。即插即用的微泵系统的可能性使我们能够轻松展示我们的设备用于通过使用有色流体和荧光纳米颗粒作为概念验证来跟踪微混合器的混合和稀释性能的可行性和工作特性。利用PMMA良好的透明度，可以实现空间液体组成并更好地控制反应变量，还可以在荧光显微镜下对实验进行实时监测。本文展示的工具易于集成到更复杂的芯片实验室平台中。
