3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
Department of Chemistry, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, Portugal.
Mater Sci Eng C Mater Biol Appl. 2019 Apr;97:851-863. doi: 10.1016/j.msec.2018.12.040. Epub 2018 Dec 28.
Microfluidics has become an important tool to engineer microenvironments with high precision, comprising devices and methods for controlling and manipulating fluids at the submillimeter scale. A specific branch of microfluidics comprises open fluidic systems, which is mainly characterized by displaying a higher air/liquid interface when compared with traditional closed-channel setups. The use of open channel systems has enabled the design of singular architectures in devices that are simple to fabricate and to clean. Enhanced functionality and accessibility for liquid handling are additional advantages inputted to technologies based on open fluidics. While benchmarked against closed fluidics approaches, the use of directly accessible channels decreases the risk of clogging and bubble-driven flow perturbation. In this review, we discuss the advantages of open fluidics systems when compared to their closed fluidics counterparts. Platforms are analyzed in two separated groups based on different confinement principles: wall-based physical confinement and wettability-contrast confinement. The physical confinement group comprises both open and traditional microfluidics; examples based on open channels with rectangular and triangular cross-section, suspended microfluidics, and the use of narrow edge of a solid surface for fluid confinement are addressed. The second group covers (super)hydrophilic/(super)hydrophobic patterned surfaces, and examples based on polymer-, textile- and paper-based microfluidic devices are explored. The technologies described in this review are critically discussed concerning devices' performance and versatility, manufacturing techniques and fluid transport/manipulation methods. A gather-up of recent biomedical applications of open fluidics devices is also presented.
微流控技术已经成为一种高精度构建微环境的重要工具，包括用于控制和操纵亚毫米级流体的设备和方法。微流控技术的一个特定分支包括开放式流体系统，其主要特点是与传统的封闭通道装置相比，具有更高的气/液界面。开放式通道系统的使用使得在设备中设计具有独特结构的器件成为可能，这些器件易于制造和清洁。增强的液体处理功能和可及性是基于开放式流体技术的附加优势。与封闭流体方法相比，直接可访问通道的使用降低了堵塞和气泡驱动的流动扰动的风险。在这篇综述中，我们讨论了开放式流体系统与封闭流体系统相比的优势。根据不同的限制原理，将平台分为两组进行分析：基于壁的物理限制和润湿性对比限制。物理限制组包括开放式和传统微流控；讨论了基于具有矩形和三角形横截面的开放式通道、悬浮微流控以及使用固体表面的窄边缘进行流体限制的示例。第二组涵盖（超）亲水/（超）疏水图案化表面，探索了基于聚合物、纺织品和纸张的微流控器件的示例。本文综述中描述的技术在设备性能和多功能性、制造技术以及流体传输/处理方法方面进行了批判性讨论。还介绍了开放式流体设备的一些最近的生物医学应用。
