Analysis Of Second-order Low-pass Microfluidic Filter

In recent years,microfluidic systems have been developed rapidly due to its outstanding advantages in miniaturization.At present,the research of microfluidic system is usually limited to a relatively stable laminar flow,similar to the development of electronics from DC to AC,microfluidic technology will use the alternating pressure as the driving source in the future.Microfluidic system alternating flow path will become the trend of the research.In the alternating microfluidic system,the micro wave filter plays the role of steady voltage,steady flow and frequency selection,so it is very important to study the micro fluidic filter.This paper consists of three parts:(1)designed a new ? type microfluidic filter structure.The structure is consist of three rectangular micro-channels with the same size and two micro cavities with the same size;(2)established a numerical simulation model of microfluidic two order low-pass filter,and analyzed the transfer function of the filter;(3)analysis the influence of channel key size parameters on filter characteristics.The bandwidth characteristics of the filter are analyzed by changing the width to depth ratio of the microchannel,the number of micro cavities and the radius of the micro-cavity.The results show that,with the micro channel width to depth ratio increases,the cutoff frequency of a filter according to the exponential decay;with the increase of micro cavity number,the effect of constant current and voltage increases;the cutoff frequency decreases exponentially with the increase of micro cavity radius.