This study reports 3D numerical analysis and experimental results to identify the optimal operating parameters of the microfluidic co-culture platform with an integrated pressure-controlled valve. This device is expected to be a valuable new tool in a wide range of studies, including basic research on intercellular communication and cell-to-cell interactions. A combination of xurography and 3D printing rapid-prototyping techniques is used to fabricate the cell co-culture microfluidic platform with a hydraulically controlled valve. Alternation of the position of the PDMS valve permits individual manipulation of the cellular microenvironment of the two adjacent cell culture chambers (27.5 mm× 35 mm× 10 mm) . The upper chamber of the device is fabricated out of PDMS while the lower channel wall consists of glass. Injection of water into a pressure chamber activates the hydraulic valve by bending the top PDMS wall of the device and pressing the barrier into contact with the bottom glass wall to isolate the two cell chambers completely. When the water is removed, and the pressure is released, the formed gap between the two cell lines permits the exchange of conditioned media between the two cell populations. The numerical analysis allows us to identify which combinations of properties (e.g., membrane thickness, PDMS composition, etc.) will allow for proper functionality by using a reasonable volume of water to actuate the valve mechanism. The model demonstrates the deflection profile of the valve in the vertical direction for multiple combinations of various valve membrane thicknesses (0.2 mm to 1 mm), water head (15 mm to 50 mm), and PDMS compositions as a ratio of curing agent and base weight (1:10, 1:20 and 1:30). The standard calibration curve presented by Wang et al. (Wang et al., 2014) is implemented to calculate the Young’s modulus for the different cross-linker amount of PDMS. Numerical simulations show that the deflection of the membrane is inversely proportional to the valve membrane thickness and directly proportional to the water head. Therefore, the parametric sweep of the model indicates that, for any combination of water heads and PDMS compositions, 0.2 mm membrane thickness provides the maximum deflection of the valve, whereas 1 mm shows the lowest. For standard PDMS composition (1:10 of the curing agent and base) and 0.2 mm membrane thickness, the maximum deflection of the valve increases from 0.83 mm to 1.23 mm when the water head is raised from 15 mm to 50 mm. Elasticity of the valve also plays a vital role in obtaining larger deflections. Maximum deflection of the valve reaches 1.58 mm for membrane thickness of 0.2 mm, water head of 50 mm, and PDMS curing agent and the base ratio of 1:30, which is an increase by 28.4% compared to the deflection for same water head and membrane thickness with standard PDMS composition.

 


Numerical Analysis of Optimal Design Parameters for a Cell Co-Culture Microfluidic Platform With an Integrated Pressure-Controlled Valve

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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