Research On Microfluidic Control Technology Based On Surface Acoustic Wave

In the past few decades,microfluidic technology has been extensively developed.As technology for processing a small amount of fluids of micro-nano size,although it is still in the development stage,it has been applied in various fields such as biology,medicine,and optics.Besides,surface acoustic wave(SAW)technology is gradually emerging,and its applications are currently mainly concentrated in the fields of drive and sensing.With the rise of the concept of lab-on-a-chip and the gradual maturity of Micro Electro Mechanical Systems(MEMS)technology,Acoustofluidics technology,which combines SAW technology with microfluidic technology,is considered to be an effective and promising technology.This technology has the advantages of simplicity,efficiency,stability,and reliability.It can produce different microfluidic driving effects by adjusting related parameters.In addition,SAW devices also have the advantages of simple structure,rapid response,programmable control.Therefore,extensive research has been initiated in the field of microfluidics.In this work,we mainly studied the droplet manipulation behavior driven by SAW.A variety of SAW devices with different structures were fabricated by depositing Zn O piezoelectric films on aluminum and silicon wafers of different thicknesses.Based on the prepared SAW devices,two kinds of research were mainly carried out on driving droplet ejection by the SAW,and using SAW to influence the impact of droplet on a solid surface.The influence of related factors was explored.The main research contents and innovative achievements of this paper are as follows:1.The surface acoustic wave technology and microfluidic technology,as well as related applications,are briefly introduced.2.The basic composition of the SAW device is introduced,and the design of related structural parameters is analyzed.Also,we analyze the acoustic flow effect and the force acting on microfluidic.3.The experimental platform is set up,and the relevant parameters that may affect the jetting angle of the droplet driven by the surface acoustic wave are systematically explored.The Zn O/Al SAW device is innovatively used to maximize the jetting angle of 55°by adjusting the relevant parameters,and the controllable jetting is realized within this range.4.The SAW is innovatively applied to the droplet impact on a solid surface.The changes in contact time under different conditions were compared and studied to minimize the contact time.In the end,we summarize the shortcomings of this work and look forward to the development.