采用步进电机的微流控芯片气压驱动系统压力特性研究

Pressure characteristics of pneumatic microfluidic chip system driven by stepper motor

针对目前气动微流控芯片控制系统微型化集成化的需求,提出了一种采用步进电机的微流控芯片气压驱动系统,通过控制器信号驱动步进电机,使PDMS流道产生了形变从而改变了阀口开度,实现了气体容腔的压力控制,对微阀的流量和气体容腔的压力进行了分析,采用Simulink搭建非线性模块,建立了系统的仿真模型,对系统的压力特性进行了仿真,得到了在不同的步进电机阶跃信号作用下的气压驱动系统压力的动态响应特性,并搭建了试验平台进行了验证。结果表明:试验结果与仿真结果基本吻合,该系统能够较快地响应于气压容器,阀口开度越大,气体容器的压力上升越快,稳定压力越高。

Aiming at the request of miniaturization and integration of microfluidic chip,a pneumatic microfluidic chip system driven by a stepper motor was presented. A controller signal was sent to the stepper motor,and the valve opening was changed by deforming the PDMS channel. The simulation model was built by using Simulink nonlinear module after analyzing the flow rate of the micro valve and the pressure of the gas container. The pressure dynamic response characteristics of the pneumatic microfluidic chip system on different step signal of the stepper motor were given based on simulation. The pressure characteristic test curves of the gas container were obtained and compared with the simulation results by building a test platform. The results indicate that pressure characteristics of pneumatic microfluidic chip system through experiment are basically the same with the simulation results. The response of system is quick to the pressure cavity. When the valve opening is larger,the pressure of the gas container rises more quickly and higher.