Membrane-activated microfluidic rotary devices for pumping and mixing

Abstract

Microfluidic devices are operated at a low-Reynolds-number flow regime such that the transportation and mixing of fluids are naturally challenging. There is still a great need to integrate fluid control systems such as pumps, valves and mixers with other functional microfluidic devices to form a micro-total-analysis-system. This study presents a new pneumatic microfluidic rotary device capable of transporting and mixing two different kinds of samples in an annular microchannel by using MEMS (Micro-electro-mechanical-systems) technology. Pumping and mixing can be achieved using a single device with different operation modes. The micropump has four membranes with an annular layout and is compact in size. The new device has a maximum pumping rate of 165.7 microL/min at a driving frequency of 17 Hz and an air pressure of 30 psi. Experimental data show that the pumping rate increases as higher air pressure and driving frequency are applied. In addition, not only can the microfluidic rotary device work as a peristaltic pumping device, but it also is an effective mixing device. The performance of the micromixer is extensively characterized. Experimental data indicate that a mixing index as high as 96.3% can be achieved. The developed microfluidic rotary device can be easily integrated with other microfluidic devices due to its simple and reliable PDMS fabrication process. The development of the microfluidic rotary device can be promising for micro-total-analysis-systems.

Size-controlled synthesis of gold nanoparticles using a micro-mixing system

“…Micro-mixers are usually classified into two categories such as active or passive devices (Auroux et al 2002). Active mixing indicates applying external forces to enhance the mixing efficiently in microchannels (Tseng et al 2007;Hsiung et al 2007). For instance, a microfluidic reaction chip integrating a micromixer, micro-pumps, a micro-valve, micro-heaters and a micro temperature sensor on a single chip was reported for synthesis of dispersed gold nanoparticles (Weng et al 2008).…”

Lab-on-a-chip: a component view

“…Control circuits and electromagnetic valves are developed by Wang and Lee (2005) to control the motion of pumps. Tseng et al (2007) utilized a microcontroller to control the driving of electromagnetic valves to generate pumping and mixing effects. A controller employed by Fu et al (2002) consisting of 3-way pneumatic switch valves digitally controlled by a National Instruments card via a fast zener diode circuit to generate peristaltic pumping action.…”

A multi‐functional electrochemical sensing system using microfluidic technology for the detection of urea and creatinine

“…The micromixer is actuated at 7 Hz with an applied pressure of 5 psi. The experimental data reveal that almost complete mixing of deionized water and black ink is completed within 1.5 s. A mixing index (s) is used to quantify the mixing performance of the micromixers and is defined as follows [29]:…”