Constructing Silk Fibroin-Based Three-Dimensional Microfluidic Devices via a Tape Mask-Assisted Multiple-Step Etching...

Area of Science:

• Biomaterials Engineering
• Microfluidics
• Materials Science

Background:

• Regenerated silk fibroin (RSF) shows promise for microfluidic devices.
• Fabricating 3D RSF microfluidic devices cost-effectively remains a challenge.

Purpose of the Study:

• To develop a facile and low-cost method for fabricating 3D microfluidic devices using RSF films.
• To demonstrate the capability of creating complex 3D structures and functional devices.

Main Methods:

• A tape-mask-assisted multiple-step etching technique using LiBr solution was employed.
• Water-annealed RSF films were etched iteratively to create 3D features.
• Control over etching parameters allowed tailoring of structure dimensions and shapes.

Main Results:

• Successfully fabricated convex-pyramid and concave-step structures on RSF films.
• Developed 3D RSF micromixers with efficient liquid mixing.
• Created RSF microfluidic separators demonstrating size-dependent particle sorting.
• RSF devices showed environmentally friendly enzymatic degradation.

Conclusions:

• The proposed tape-assisted etching technique offers a simple, cost-effective route to 3D RSF microfluidic devices.
• This method expands the application potential of RSF in biomedical and chemical analysis.
• The fabricated devices exhibit promising performance in mixing and particle separation.