Development of a Tool for Verifying Leakage Detection in Microfluidic Systems

Area of Science:

• Biomedical Engineering
• Materials Science
• Fluid Dynamics

Background:

• Microfluidic devices are increasingly submitted to regulatory bodies like the Food and Drug Administration (FDA).
• Leakage is a prevalent and challenging failure mode in microfluidic systems, impacting device reliability and safety.
• Accurate detection and quantification of microfluidic leaks are crucial for medical device development.

Purpose of the Study:

• To develop and validate a sensitive tool for measuring and verifying microfluidic leakages.
• To establish a bench test method for assessing leak rates from 0.1% to 10% in microfluidic systems.
• To provide a verification tool for developers of microfluidic medical devices to detect flow-mediated leakage failures.

Main Methods:

• An analytical model was developed applying hydrodynamic resistance principles to fluid-contacting elements (tubing, junctions, connectors).
• Leakage rates were tuned based on application-specific acceptance criteria.
• Three polymer-based microfluidic systems (PEEK, PEEKsil, COC) were used to target and experimentally verify leakages at approximately 0.1%, 1.0%, and 10% levels.

Main Results:

• The PEEKsil tubing system demonstrated high accuracy with experimental uncertainties of 0.00% to 1.59% across target leak rates.
• Polyether Ether Ketone (PEEK) tubing showed higher uncertainties, ranging from 1.16% to 23.08%.
• Cyclic Olefin Copolymer (COC) microfluidic chips exhibited errors of 7.69% and 5.05% for specific target leakages.

Conclusions:

• The proposed bench test method offers a sensitive and reliable approach for leakage detection in microfluidic devices.
• The methodology allows for precise tuning of leakage rates, aiding in the verification of leakage detection systems.
• This tool can significantly assist device developers in assessing and mitigating leakage-related failures in microfluidic medical applications.