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Microfluidic Picoliter Bioreactor for Microbial Single-cell Analysis: Fabrication, System Setup, and Operation
Published on: December 6, 2013
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Microfluidic bubbler facilitates near complete mass transfer for sustainable multiphase and microbial processing
Jordan J Baker1, Francesca Crivellari1, Zachary Gagnon2
1Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., Maryland Hall 221, Baltimore, MD, 21218.
Biotechnology and Bioengineering
|March 2, 2016
Summary
A novel microfluidic device generates micro-bubbles for highly efficient mass transfer, significantly improving gas transfer in bioreactors with reduced flow rates. This technology offers a more sustainable approach to multiphase processes.
Area of Science:
- Biotechnology
- Chemical Engineering
- Microfluidics
Background:
- Efficient gas-liquid mass transfer is crucial for many industrial processes, including bioreactors.
- Traditional bubbling methods often suffer from low efficiency, especially at low flow rates, and high energy consumption.
- Microfluidic devices offer potential for enhanced interfacial processes due to their unique channel geometries and flow characteristics.
Purpose of the Study:
- To develop and evaluate a microfluidic device for generating micro-bubbles to enhance mass transfer efficiency.
- To compare the performance of the microfluidic device with conventional bubbling methods.
- To assess the application of the microfluidic device in an algae bioreactor for improved CO2 transfer and biomass production.
Main Methods:
- A microfluidic device with channels less than 70 μm was designed with a Y-junction to generate micro-bubbles through pressure changes.
- Bubble generation and mass transfer coefficients (KL a) were measured at low flow rates.
- The device's performance was tested in an algae bioreactor, comparing CO2 absorption and cell density with a needle bubbling method.
Main Results:
- The microfluidic device produced bubbles with an average diameter of 110 μm, achieving a volumetric mass transfer coefficient (KL a) of 1.43 h⁻¹.
- Normalized KL a values indicated a 100-fold increase in transfer efficiency compared to four other bubblers.
- Oxygen transfer reached approximately 90%, and in the algae bioreactor, the microbubbler absorbed 90% of CO2 feed, leading to higher cell density with significantly lower flow rates.
Conclusions:
- Microfluidic devices can significantly enhance gas-liquid mass transfer efficiency at low flow rates by generating micro-bubbles.
- This technology offers a substantial improvement over conventional bubbling methods, demonstrated by increased CO2 transfer and biomass yield in an algae bioreactor.
- Microfluidics holds promise for transforming interfacial processing, enabling more sustainable and efficient multiphase systems with minimized gas input.
