Rodrigues Rodolfo G, Condelipes Pedro G M, Rosa Rafaela R, Chu Virginia, Conde João Pedro
Instituto de Engenharia de Sistemas e Computadores-Microsistemas e Nanotecnologias (INESC MN), Rua Alves Redol 9, 1000-029 Lisbon, Portugal.
Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal.
Micromachines (Basel). 2023 Sep 27;14(10):1837. doi: 10.3390/mi14101837.
Microfluidics evolved with the appearance of polydimethylsiloxane (PDMS), an elastomer with a short processing time and the possibility for replication on a micrometric scale. Despite the many advantages of PDMS, there are well-known drawbacks, such as the hydrophobic surface, the absorption of small molecules, the low stiffness, relatively high cost, and the difficulty of scaling up the fabrication process for industrial production, creating a need for alternative materials. One option is the use of stiffer thermoplastics, such as the cyclic olefin copolymer (COC), which can be mass produced, have lower cost and possess excellent properties. In this work, a method to fabricate COC microfluidic structures was developed. The work was divided into process optimization and evaluation of material properties for application in microfluidics. In the processing step, moulding, sealing, and liquid handling aspects were developed and optimized. The resulting COC devices were evaluated from the point of view of molecular diffusion, burst pressure, temperature resistance, and susceptibility to surface treatments and these results were compared to PDMS devices. Lastly, a target DNA hybridization assay was performed showing the potential of the COC-based microfluidic device to be used in biosensing and Lab-on-a-Chip applications.
微流控技术随着聚二甲基硅氧烷（PDMS）的出现而发展，PDMS是一种加工时间短且能够在微米尺度上进行复制的弹性体。尽管PDMS有诸多优点，但也存在一些众所周知的缺点，比如疏水表面、小分子吸收、低刚度、成本相对较高以及难以扩大制造工艺以进行工业生产，这就催生了对替代材料的需求。一种选择是使用刚度更高的热塑性塑料，比如环烯烃共聚物（COC），它可以大规模生产、成本更低且具有优异的性能。在这项工作中，开发了一种制造COC微流控结构的方法。这项工作分为工艺优化以及对微流控应用中材料性能的评估。在加工步骤中，对成型、密封和液体处理方面进行了开发和优化。从分子扩散、破裂压力、耐热性以及对表面处理的敏感性等角度对所得的COC器件进行了评估，并将这些结果与PDMS器件进行了比较。最后，进行了目标DNA杂交分析，展示了基于COC的微流控器件在生物传感和芯片实验室应用中的潜力。
