System-level simulation of liquid filling in microfluidic chips.

Area of Science:

• Microfluidics
• Computational Fluid Dynamics
• System-level Modeling

Background:

• Liquid filling in microfluidic channels is crucial for chip functionality but challenging to model accurately.
• Existing high-fidelity methods (e.g., Volume of Fluid) are computationally expensive.
• Analytical models are limited to simple geometries, failing to capture complex network behavior.

Purpose of the Study:

• To develop a parametrized dynamic model for system-level analysis of liquid filling in 3D microfluidic networks.
• To enable rapid and accurate simulation of the liquid filling process.
• To facilitate design optimization of complex microfluidic systems.

Main Methods:

• Deconstructing complex microfluidic networks into basic components (reservoirs, channels, junctions).
• Developing a dynamic model based on the transient momentum equation to track liquid fronts.
• Utilizing mass conservation at junctions to link parameters and assembling component models into a system of differential-algebraic equations.

Main Results:

• The system-level model accurately simulates transient liquid filling in various microfluidic constructs and a multiplexer.
• Achieved significant speedups (30,000X-4,000,000X) compared to high-fidelity simulations with less than 7% relative error.
• Demonstrated the model's utility for fast and reliable analysis of liquid filling dynamics.

Conclusions:

• The proposed parametrized dynamic model provides an efficient and accurate approach for system-level analysis of liquid filling in complex 3D microfluidic networks.
• This methodology aids in evaluating design parameters, predicting filling times, and optimizing microfluidic chip designs.
• The model offers a valuable tool for accelerating the design and development of advanced microfluidic devices.