Microfluidic Manipulation in Lab-chips Using Electrorheological Fluid

Abstract

Microfluidic manipulation is one of the main concerns in lab-chip society. This article presents the design, fabrication and testing methodologies of electrorheological (ER) fluid-controlled active microfluidics chips. All of the fundamental building blocks, such as microvalves, micropumps and micromixers, are fabricated with similar processes in PDMS-based chips for easy integration. Such building blocks can be digitally controlled by on—off switching of electric fields applied on the parallel electrodes along the ER fluid channels. Experimental results show reliable functionalities of these devices. The ER active control scheme supplies additional flexibilities over the passive control of microfluidics. A hybrid approach of active mixers, combining the ER active actuation with the passive baffle structures, was applied to achieve more efficient chaotic mixing than the passive mixers available.