Membrane-activated microfluidic rotary devices for pumping and mixing

Area of Science:

• Microfluidics
• MEMS technology
• Biomedical engineering

Background:

• Microfluidic devices operate at low Reynolds numbers, posing challenges for fluid transport and mixing.
• Integrating essential fluid control systems (pumps, valves, mixers) into microfluidic devices is crucial for creating micro-total-analysis-systems (µTAS).

Purpose of the Study:

• To present a novel pneumatic microfluidic rotary device for simultaneous fluid transport and mixing.
• To demonstrate the device's capability using Micro-Electro-Mechanical-Systems (MEMS) technology.

Main Methods:

• Fabrication of a compact, annular micropump with four membranes using PDMS.
• Characterization of the device's pumping performance under varying air pressure and driving frequency.
• Evaluation of the device's mixing efficiency in an annular microchannel.

Main Results:

• The micropump achieved a maximum pumping rate of 165.7 µL/min at 17 Hz and 30 psi.
• Pumping rate increased with higher air pressure and driving frequency.
• A mixing index as high as 96.3% was achieved, demonstrating effective mixing capabilities.

Conclusions:

• The developed microfluidic rotary device integrates pumping and mixing functions in a single unit.
• Its simple and reliable PDMS fabrication facilitates integration with other microfluidic components.
• The device shows significant promise for advancing micro-total-analysis-systems.