Faculty

Science

Supervisor Name

Tamie Poepping

Keywords

Shear stress, oscillatory flow, microfluidic chip, vascular disease, endothelial cells, particle image velocimetry

Description

Purpose: To demonstrate the effectiveness of a novel microfluidic device mimicking oscillatory blood flow, allowing cell biologists to examine how endothelial cells respond to a range of oscillatory shear stress levels.

Methods: The microfluidic chip consists of a circular-shaped reservoir, leading to a rectangular channel that is examined under a microscope. The plunger is connected to a speaker system and oscilloscope, allowing the plunger to apply a range of frequencies (5-60Hz) and voltages (5-10 V, leading to a variety in oscillation amplitudes) to the reservoir region. 1.1 um fluorescent particles diluted in distilled water were used for tracking. Processing was done through particle image velocimetry (PIV) which uses a cross-correlation algorithm. We used matlab to plot average velocity profiles for a cycle, and extracted data points along the centre of the velocity profiles corresponding to the maximum velocities.

Results: The oscillatory chip demonstrated the ability to effectively and accurately deliver oscillatory flow between 10-60Hz using 5-10V, resulting in a variety of oscillation frequencies and amplitudes. Plotting velocity maximum values vs. voltage for frequencies 10-60 Hz demonstrated a linear trend. 3D oscillatory-flow paraboloids can be used in calculating maximum shear stress values for oscillatory flow.

Conclusions: Our analysis demonstrates that this microfluidic chip is able to execute controlled shear stress conditions to test how endothelial cells respond to oscillatory shear.

Acknowledgements

Thank you to Dr. Poepping for her endless advice, positivity, and patience. Thank you to members of the Poepping, Holdsworth, Dixon, and Sims labs for their support and guidance. This project would not be possible without the funding by WUSRI, NSERC, and CIHR

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Document Type

Poster

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Producing and Measuring Oscillatory Shear in a Novel Microfluidic Chip

Purpose: To demonstrate the effectiveness of a novel microfluidic device mimicking oscillatory blood flow, allowing cell biologists to examine how endothelial cells respond to a range of oscillatory shear stress levels.

Methods: The microfluidic chip consists of a circular-shaped reservoir, leading to a rectangular channel that is examined under a microscope. The plunger is connected to a speaker system and oscilloscope, allowing the plunger to apply a range of frequencies (5-60Hz) and voltages (5-10 V, leading to a variety in oscillation amplitudes) to the reservoir region. 1.1 um fluorescent particles diluted in distilled water were used for tracking. Processing was done through particle image velocimetry (PIV) which uses a cross-correlation algorithm. We used matlab to plot average velocity profiles for a cycle, and extracted data points along the centre of the velocity profiles corresponding to the maximum velocities.

Results: The oscillatory chip demonstrated the ability to effectively and accurately deliver oscillatory flow between 10-60Hz using 5-10V, resulting in a variety of oscillation frequencies and amplitudes. Plotting velocity maximum values vs. voltage for frequencies 10-60 Hz demonstrated a linear trend. 3D oscillatory-flow paraboloids can be used in calculating maximum shear stress values for oscillatory flow.

Conclusions: Our analysis demonstrates that this microfluidic chip is able to execute controlled shear stress conditions to test how endothelial cells respond to oscillatory shear.

 

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