Microfluidic T-Form Mixer Utilizing Switching Electroosmotic Flow

This paper presents a microfluidic T-form mixer utilizing
alternatively switching electroosmotic flow. The microfluidic device is fabricated on low-cost glass slides using
a simple and reliable fabrication process. A switching DC
field is used to generate an electroosmotic force which
simultaneously drives and mixes the fluid samples. The
proposed design eliminates the requirements for moving
parts within the microfluidic device and delicate external
control systems. Two operation modes, namely, a conventional switching mode and a novel pinched switching
mode, are presented. Computer simulation is employed
to predict the mixing performance attainable in both
operation modes. The simulation results are then compared to those obtained experimentally. It is shown that
a mixing performance as high as 97% can be achieved
within a mixing distance of 1 mm downstream from the
T-junction when a 60 V/cm driving voltage and a 2-Hz
switching frequency are applied in the pinched switching
operation mode. This study demonstrates how the driving
voltage and switching frequency can be optimized to yield
an enhanced mixing performance. The novel methods
presented in this study provide a simple solution to mixing
problems in the micro-total-analysis-systems field.