气动微流控芯片PDMS电磁微阀设计与性能研究

Design and characterization study on PDMS electromagnetic microvalve for pneumatic lab-on-a-chip

针对常规电磁阀和阀组结构复杂、尺寸巨大,很难与微流控芯片进行集成的问题,采用新型阀体材料高弹PDMS,设计了一种新型电磁微阀.通过Fluent软件嵌入UDF函数对典型驱动压力下不同阀口开度电磁微阀的静、动态流量特性进行数值仿真,并对开关和脉冲宽度调制(PWM)两种模式下电磁微阀流量特性进行了实验研究,结果表明:在驱动频率相等的情况下,电磁微阀流量与压差呈正比;当压差一定时,电磁微阀流量与驱动频率呈反比,电磁微阀平均流量与占空比呈正比;电磁微阀出口流量与阀口开度呈正比.所设计的电磁微阀流量控制精度高、封装成本低,能够提高微流控芯片的集成化程度和控制性能.

Inview of the complicated structure and the large size of the regular electromagnetic valve and valve block and the difficulty in their integration with micro-fluidic chip, a new type of the electromagnetic microv-alve was designed using PDMS, a new type of valve body. The numerical simulation of the static and dynamic flow rate characteristics of the electromagnetic microvalves with different valve-openings was made by Fluentsoftware with UDF function under typical driving pressure. And experiment was made on the flow characteris- tics of electromagnetic microvalves under On-Off model and PWM model. The results showed that under thesame driving pressure, electromagnetic valve flow was proportional to its pressure difference; under the same pressure difference, the average flow of electromagnetic valve was inversely proportional to its driving fre-quency and its opening flow was proportional to its duty cycle. The designed electromagnetic microvalve had high flow control precision, low cost of encapsulation and could improve the integration and control of pneu-matic micro-fluidic chip.