摘要
为了克服离心式微流控芯片上血清提取对虹吸管亲水性的依赖,保证离心式微流控芯片功能的稳定性和可靠性,在芯片上设计了连接于血液分离腔的压缩空气腔,实现了高转速下血液的分离。基于压缩空气的辅助作用,并通过转速降低导致压缩空气腔内所储存气体压强的释放对血清的泵送作用,实现了离心式微流控芯片上血清的定量提取。基于等温气体的热力学平衡理论,分析了压缩空气腔压缩体积和虹吸管内液面位置与电机转速之间的关系,给出了基于压缩空气辅助作用的离心式血清提取结构的设计规律。以聚甲基丙烯酸甲酯(PMMA)为基材,采用CO2激光加工工艺,制作了离心式血清提取芯片,并测试了不同转速下被压缩气体的体积和血清液面在虹吸管中的位置。实验结果表明:转速为4000r/min时,空气的被压缩量为8.7μL,虹吸管能有效抑制全血溢出以防止全血进入血清提取腔;当转速降为1000r/min时,压缩气体所储存压强得到释放,克服了离心力,并驱动血清流过虹吸管最高点,进而实现血清的定量提取。
To overcome the dependence of the plasma extraction on siphon hydrophilicity in a centrifugal mi- crofluidic chip and to ensure lon-term stability and reliability of the microfluidic chip, a compressed air reser- voir connected to the blood separated reservoir was proposed to separate the blood in blood separated reservoir at high rotating speeds. Through lowering the spinning speed, the plasma in the separated reservoir waspumped toward the CD-like chip center to release the stored air pressure produced by the rotation at high spin- ning speeds. Based on the thermodynamics of the isothermal gas, the pneumatic pumping method was mod- eled, and the model was confirmed by analyzing pumping positions and air compression versus spinningspeeds. By using the layered Polymethyl Methacrylate（PMMA）as materials, the centrifugal microfluidic chips for plasma extraction were fabricated with a CO2 laser process technique and the volume of compressed air and the blood position at siphon were tested at different rotational speeds. Experimental results demonstrate thatthe achieved volume of compression is 8.7μL and the siphon valve effectively inhibits whole blood to overflow the crest of siphon at 4 000 r/min speed. With lowering the spin speed to 1 000 r/min, the release of com-pressed air overcomes the centrifugal force and drives the plasma to flow past the crest of siphon. Then the plasma extraction is realized in quantitation.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2014年第10期2733-2739,共7页
Optics and Precision Engineering
基金
国家863高技术研究发展计划资助项目(No.2012AA040503)
国家自然科学基金资助项目(No.5120538)
关键词
压缩空气泵
离心式微流控芯片
血清提取
虹吸阀
离心力
compressed air pump
CD-like microfluidic chip
plasma extraction
siphon valve
centrif-ugal force
