Microbubble generation in a co-flow device operated in a new regime
Elena Castro-Hernández1, Wim van Hoeve, Detlef Lohse
1Área de Mecánica de Fluidos, Departamento de Ingeniería Aeroespacial y Mecánica de Fluidos, Universidad de Sevilla, Avda. de los Descubrimientos s/n, 41092 Sevilla, Spain.
Lab on a Chip
|March 25, 2011
Summary
Researchers developed a new method for creating tiny, uniform microbubbles in microfluidic devices. This technique allows for precise control over bubble size, crucial for therapeutic applications and achieving high production rates.
Area of Science:
- Microfluidics
- Bubble Dynamics
- Biomedical Engineering
Background:
- PDMS-based flow-focusing microfluidic devices are commonly used for fluid manipulation.
- Producing monodisperse microbubbles with controlled sizes is challenging, especially for therapeutic applications.
Purpose of the Study:
- To present a new operational regime for PDMS microfluidic devices to generate monodisperse microbubbles.
- To demonstrate precise control over microbubble size and production rate.
Main Methods:
- Utilizing a strong pressure gradient in the entrance region of a flow-focusing microfluidic device.
- Generating bubbles at the tip of a stable gas ligament with a diameter smaller than the channel width.
- Tuning gas and liquid flow rates to control bubble ligament diameter and volume.
Main Results:
- Achieved production of monodisperse microbubbles with diameters below one-tenth of the channel width (w = 50 μm).
- Demonstrated control over bubble volume spanning over two orders of magnitude.
- Developed a scaling theory predicting bubble diameter: d(b)/w ∝ (μ(g)/μ(l))(1/12)(Q(g)/Q(l))(5/12).
- Produced 5 μm microbubbles suitable for therapeutic applications at rates exceeding 10^5 Hz.
Conclusions:
- The new regime enables efficient and controlled generation of monodisperse microbubbles.
- The findings are applicable to therapeutic applications requiring precise microbubble sizing and high production rates.
- The developed scaling theory accurately describes the experimental results for bubble diameter control.
