Research On Performance Of Microfluidic Multi-chamber Piezoelectric Peristaltic Micropump

Micropump is widely applied in the field of microfluidic actuation and control due to its small size and easy integration with other devices.Peristaltic micropump,as a subclass of micropump,can realize the directional flow and transportation of liquid in microchannel by squeezing the fluid towards a certain direction by the peristalsis of the pump chamber.The mentioned peristaltic micropump here has a significant characteristic of separated actuator from microfluidic chip,which enables abilities of low cost,plug-and-play,and no cross contamination.At present,the peristaltic micropump consists of 3 actuators and 3 corresponding micro-chambers generally.The actuator squeezes and releases its corresponding micro-chamber according to a settled time order to pump the fluid peristaltically.Traditional peristaltic micropump with 3 chambers with relatively lower backpressure,however,leads to liquid reflux easily,limiting the application of peristaltic micropump.In this paper,a piezoelectric-driven peristaltic micropump system is designed to overcome the low backpressure,while the influence of the number of peristaltic micropump chambers on the backpressure and flow range are also demonstrated.Experiments were conducted focusing on the influences of actuator working mode on the performance of peristaltic micropump.The specifics are as follows:(1)Theoretical model establishment and the simulation of peristaltic micropump with multi-chamber:demonstrating the woridng mechanisms and establishing the theoretical model for peristaltic micropump with multi-chamber;finite element simulation of working process of peristaltic micropump based on Ansys simulation software and dynamic simulation technology;simulating the flowing deformation of microchamber and the flow state of liquid in microchannel during the pumping process;analyzing the association between the number of peristaltic micropump chambers and its performance.(2)Construction and manufacture of piezoelectric peristaltic micropump system with multi-chamber:a microfluidic chip with micro-channel structure,composed of PDMS(polydimethylsiloxane)and glass slide was designed and manufactured by using MEMS technology.With the integration with multiple independent piezoelectric-drive units,a peristaltic micropump system based on piezoelectric-drive was built.(3)Performance characterization of piezoelectric peristaltic micropump with multi-chamber:performing experiments to evaluate the effect of the number of peristaltic micropump chambers on its performance;verifying the accuracy of theoretical model and simulation analysis;The results showed that the reverse backpressure of five-chamber micropump could be increased maximumly by 2.4 times compared with that of three-chamber micropump,to be specific,with a driving voltage of 120 V and a frequency of 100 Hz,the reverse backpressure could up to 12 kPa,while the flow rate could reach 15.85μL/min.(4)Optimization of the working mode of the five-chamber piezoelectric peristaltic micropump:8 working modes with different time orders of actuator are proposed and analyzed under the same condition(driving voltage 100 V and frequency 50 Hz).The best working mode is put forward without changing the structure of microfluidic chip after analyzing the impact of actuator working mode on the performance of peristaltic micropump.The results of this investigation can not only guide the development of separate multi-chamber piezoelectric peristaltic micropumps,but also contribute to the design and optimization of the peristaltic micropump chip structure.