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Steady-State and Dynamic Behavior of Geometry-Tunable Microfluidic Passive Flow Regulators.
Huy Hoang Vu1, Tran Vy Khanh Vo1,2, Hafiz Muhammad Musharaf1
1Queensland Quantum and Advanced Technologies Research Institute, Griffith University, Nathan, Queensland, Australia.
Small (Weinheim an Der Bergstrasse, Germany)
|July 1, 2026
Summary
Passive flow regulators offer autonomous control but their dynamic response is unclear. This study develops a model and experiments showing geometry impacts transient dynamics, enabling predictable microfluidic system design.
Area of Science:
- Fluid Dynamics
- Microfluidics
- Control Systems
Background:
- Passive flow regulators offer autonomous fluid control without electronics.
- Their dynamic response is poorly understood, hindering integration into time-dependent systems.
Purpose of the Study:
- Investigate the dynamic response of passive microfluidic flow regulators.
- Develop a framework to predict geometry-dependent transient dynamics.
- Provide design guidelines for microfluidic systems.
Main Methods:
- Developed a reduced-order analytical framework using an electrical analogy.
- Fabricated passive microfluidic flow regulators with varying channel widths (300-700 µm) using soft lithography.
- Performed systematic steady-state and dynamic experimental characterization.
Main Results:
- Identified nonlinear flow-pressure relationships and geometry-dependent fluidic resistance.
- Observed first-order low-pass dynamic behavior driven by fluid-structure interactions.
- Found a trade-off between flow rate (throughput) and transient response (bandwidth) with channel width.
Conclusions:
- A reduced-order resistance-capacitance model accurately captures transient dynamics.
- Geometry-dependent dynamics can be predicted without complex simulations.
- Findings enable practical design of autonomous microfluidic systems with reliable performance.
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