PDMS微/毫流控芯片的简易快速制备及其疏水性研究

Convenient and Rapid Fabrication of and Hydrophobicity Study on PDMS Microfluidic/Millifluidic Chip

将玻璃片/管、锡箔等材料进行组装、通道搭建制备出带有管路图案的容器,再将聚二甲基硅氧烷(PDMS)预聚体浇注到该容器中固化成型,之后通过模具拆卸、切割制备出整体式PDMS微/毫流控芯片.该法可获取各种微通道尺寸保真性好的整体式芯片,其通道截面圆形度与由热压法制备的微流控芯片相比有明显提高.另将获得的PDMS芯片经过30 min紫外改性后,其疏水性得到明显改善,与H2O的接触角由钝角变为了锐角,并在室温下静置能维持1 h左右的改性,完全能够满足液滴成型实验的时间要求.另外将该法制备的PDMS整体式芯片用于单分散液滴、双重液滴制备时,可在较宽的流速范围(4 mL/h^36 mL/h)内得到粒径可控的液滴,并且液滴在芯片通道中不易破乳,表现出良好的稳定性.这对于靶球制备、功能材料合成、活性成分保持等应用有重要意义.

A microfluidic/millifluidic chip can be fabricated conveniently and rapidly by pouring polydimethylsiloxane （PDMS） into a removable model, which is assembled by such materials as glass sheet/tube, aluminum foil and so on. By disassembling the model and cutting needless PDMS, intact chips with high fidelity for various micro channel sizes can be prepared easily. Through an optical micro- scope, we find the roundness of this channel＇s cross profile is much better than the chip fabricated by hot pressing. After 30 rain UV modification, the PDMS chip with higher hydrophobic properties can be achieved. The contact angle with H20 is switched into an acute angle from an obtuse one. The switch in angle can last one hour or so at room temperature, which can entirely meet the requirement of the droplet experiment. In addition, the chip fabricated in this way can be used for tunable monodisperse droplet or double droplet formation in a wide flow rate （4 mlMh--36 mlMh）. In the channel, the droplet is hardly broken, indicating that the chip can provide a stable environment. It is of great significance for target ball fabricating, functional material synthesizing, and active component maintaining.