A Rapid Micromixer for Centrifugal Microfluidic Platforms

Ziliang Cai, Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, USA. zcai4@lsu.edu.
Jiwen Xiang, Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, USA. jxiang3@lsu.edu.
Hualing Chen, College of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China. hlchen@mail.xjtu.edu.cn.
Wanjun Wang, Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, USA. wang@lsu.edu.

Abstract

This paper presents an innovative mixing technology for centrifugal microfluidic platforms actuated using a specially designed flyball governor. The multilayer microfluidic disc was fabricated using a polydimethylsiloxane (PDMS) replica molding process with a soft lithography technique. The operational principle is based on the interaction between the elastic covering membrane and an actuator pin installed on the flyball governor system. The flyball governor was used as the transducer to convert the rotary motion into a reciprocating linear motion of the pin pressing against the covering membrane of the mixer chamber. When the rotation speed of the microfluidic disc was periodically altered, the mixing chamber was compressed and released accordingly. In this way, enhanced active mixing can be achieved with much better efficiency in comparison with diffusive mixing.