An Investigation On Digital Microfludic Applications For Acoustic Wave Sensing And Acoustofluidic Mixing

Lab-on-a-chip(LoC)is a technology that integrates the operations or analysis contained in the laboratory,such as DNA sequencing,biochemical detection,etc.,into a micro-scale chip,involving physics,chemistry,micromachining,bioengineering,etc.In recent years,LoC has shown great potential in medical health,new material synthesis and genetic sequencing,but it also faces many challenges in technology and commercialization.In view of the practical development of LoC,an investigation on digital microfludic applications is studied to realize integrated,diversified on-chip operation and analysis,oriented to biochemical detection and analysis.This work is expected to actively promote the growth of LoC in scientific research and commercialization for the future.In this paper,digital microfluidic chip integrated with piezoelectric resonator array is studied.Based on their working principle and structure,the integrated chip is designed and fabricated.Then,microfluidic bulk modulus sensing with the piezoelectric resonator as micro acoustic sensor of integrated chip is developed,based on the establishment of the acoustic transmission model and the physical field model.After that,acoustic wave sensing experiments are implemented,realizing on-chip automatic liquids feeding,transporting,rapid and real-time sensing and collection,which meets the practical application requirements of LoC.In addition,acoustic streaming effect with the piezoelectric resonator as actuator of integrated chip is analyzed,based on the establishment of physical field model of ~GHz longitudinal acoustic waves in liquid environment.The droplet in-situ mixing experiments under different scales are designed,realizing the automatic merging and acoustic mixing,which demonstrates the feasibility of bioassay on integrated chip.The innovative work is that all operations,including automatic real-time detection and rapid mixing of micro-droplets,are completed on the microchip,which will play an active role in the development of LoC in future disease diagnosis,biomedical research,etc.