Numerical Simulation on the Response Characteristics of a Pneumatic Microactuator for Microfluidic Chips

This article presents a multiphysical system modeling and simulation of a pneumatic microactuator, which significantly influences the performance of a particular pneumatic microfluidic device. First, the multiphysical system modeling is performed by developing a physical model for each of its three integrated components: microchannel with a microvalve, a gas chamber, and an elastomer membrane. This is done for each step of operation for the whole system. The whole system is then considered a throttle blind capacitor model, and it is used to predict the response time of the pneumatic microactuator by correlating its characteristics such as gas pressurizing, hydraulic resistance, and membrane deformation. For this microactuator, when the maximum membrane deformation is 100 µm, the required actuated air pressure is 80 kPa, and the response time is 1.67 ms when the valve-opening degree is 0.8. The response time is 1.61 ms under fully open conditions. These simulated results are validated by the experimental results of the current and previous work. A correlation between the simulated and experimental results confirms that the multiphysical modeling presented in this work is applicable in developing a proper design of a pneumatic microactuator. Finally, the influencing factors of the response time are discussed and analyzed.