Viscous Fingering in Multiport Hele Shaw Cell for Controlled Shaping of Fluids

Area of Science:

• Fluid Dynamics
• Materials Science
• Complex Systems Engineering

Background:

• Mimicking complex multiscale systems remains a significant challenge in science and engineering.
• Viscous fingering in Hele-Shaw cells typically leads to random fluid rearrangements.
• Existing methods struggle to create ordered, multiscale structures controllably.

Purpose of the Study:

• To present a novel method for engineering complex cross-linked meshes and branched structures at multiple scales.
• To demonstrate control over Saffman-Taylor instability for fabricating ordered patterns.
• To establish a foundation for new pathways in multiscale structure engineering.

Main Methods:

• Utilizing a "lifted Hele-Shaw cell" with multiple ports (source-holes).
• Controlling Saffman-Taylor instability by introducing multiple fluid sources.
• Spontaneously shaping stretched fluid films into defined webs, meshes, and tree-like patterns.

Main Results:

• Achieved robust and repeatable fabrication of well-defined multiscale structures.
• Demonstrated spontaneous formation of diverse web/mesh and tree-like patterns.
• Successfully engineered structures ranging from micro to very large scales within seconds.

Conclusions:

• The multi-port Hele-Shaw cell offers a powerful new approach for engineering complex multiscale systems.
• This technique provides a foundation for applications in gas exchange, heat transport, tissue engineering, and organ-on-chip devices.
• The method also opens avenues for studying complex fluid finger interactions and pattern formation.