Abstract: FR-PO975

Parallel Cross-Flow Filtration Microfluidic Device for Renal Micro-Environment Emulation

Session Information

Category: Bioengineering and Informatics

  • 101 Bioengineering and Informatics

Author

  • Odeh, Zach, First Affiliated Hospital of Dalian Medical University, Dalian, China
Background

Whole human blood, a non-Newtonian fluid, can effectively be filtered on a microfluidic device. Past microfluidic design approaches utilized dead-end filtration concepts that lead to clogging since the cells are trapped in the direction of flow. This limitation also precludes the filtration of plasma, an important component to investigate renal inflammation. There is a need for a novel design that can mimic capillary action and fenestrations gaps akin to the renal micro-environment. The primary aim of this study was to design, fabricate, and test a novel microfluidic device for separating whole human blood (plasma, white blood cells, and red blood cells).

Methods

Development of the microfluidic device utilizes photolithography and micro-molding techniques that involve the following basic components: silicon wafer (1 1 1), chrome masks, glass, and polydimethysiloxane (PDMS). Design assumptions called for human blood as the testing fluid. The design utilized a five-row filtration system in the first modular section with varying gap sizes (between pillar edges) from 6.5 microns to 2.5microns. The second modular design included three channels with the main channel flanked by weir micro filtration barriers of consistent gap slits of 3.5 micons.

Results

The combined (pillar and weir) cross-flow design was shown to rapidly separate different categories of blood cells simultaneously based on size-exclusion principles despite spacing anomalies. The pillar filtration segment appears to show gradient changes, especially in the last two filtration tunnels. The other weir filtration segment does not show as drastic a color gradient change.

Conclusion

This microfluidic chip, based on a multi-level parallel cross-flow design, offers enhanced features over prior microfluidic approaches. It effectively addressed dead-end filtration limitations with no visible clogging obstacles. It demonstrates a successful integration of modular micro-feature units (pillar and weir).

Modular Micro-Feature Systems