基于玻璃-PDMS复合结构的微型毛细管被动阀

A simple-fabricated passive microvalve using rapid prototyping of glass and PDMS(polydimethylsiloxane)

微阀是微流控系统中起控制限流的重要组成器件。研究的微阀是一种基于微机械加工技术的无活动部件的单向被动阀,其利用通道表面张力的变化产生阻流作用,起到阀的作用。讨论了被动阀的工作机理,利用快速制备原型技术制作微阀,同时在玻璃表面制作憎水薄膜,将玻璃与PDMS基底贴合并施加一定的压力,即可实现微阀的简单封装。取去离子水进行测试,微阀可以成功的停住液流,最大可以产生1kPa的压力降。阀的操作模式试验表明,微阀适合于应用在低压、一次性使用的场合。

Valves are important components to control flows in microfluidic system. A simple-fabricated and low-cost microvalve was presented. Microchannels with different sizes were moulded using rapid prototyping of PDMS （polydimethylsiloxane）. Pyrex glass surfaces , which are hydrophilic originally, are modified with organo-silicon compound （ dimethyldimethyloxysilane ） and octadecytrichlorosilane （OTS） self-assembled monolayer , with the contact angles 90°and 110°for water respectively. Then microchannels made on PDMS can be jointed to the Pyrex glass. Tested for deionized water, the microvalve blocks the liquid successfully, yielded pressure barrier is up to 1 kPa maximally. Operating experiment of microvalve shows it can be applied as passive valve for single using.