Evaluating Flow-Focused Microfluidic Device Fabrication Techniques for Silk Fibroin Microgel Production

Haghighattalab M, Karimi F, et al.

Advanced Materials Technologies

University of New South Wales, Tyree Foundation Institute of Health Engineering

RESEARCH SUMMARY

This study systematically compared three microfluidic device fabrication methods—maskless photolithography, laser engraving, and 3D printing—for the generation of photo-crosslinked silk fibroin microgels. Using a Ru/SPS visible-light crosslinking system, silk droplets were formed in flow-focusing PDMS devices and photocrosslinked to form spherical or rod-shaped microgels. Fabrication precision, droplet generation rates, and resulting microgel size distributions were characterized. Microgel stiffness was tunable from ~40 kPa to ~590 kPa by varying silk molecular weight (controlled via degumming time). The results demonstrate the trade-offs between fabrication accessibility, channel smoothness, and output reproducibility, highlighting low-cost pathways for scalable microgel production in tissue engineering applications.

Mechanical testing of individual silk fibroin microgels was conducted using a CellScale MicroTester LT. Each microgel was compressed between 3 × 3 mm parallel plates up to 100 µm displacement within 20 seconds. The Hertzian contact model was applied to calculate elastic modulus from displacement and force data (ε ≤ 10 %, ν = 0.5). Compressive moduli were tunable from ~40 kPa (60 min degummed silk) to ~590 kPa (10 min degummed silk), demonstrating control of stiffness through molecular weight and crosslinking density.

AUTHORS

Mahsa Haghighattalab, Fatemeh Karimi, Nona Farbehi, Jelena Rnjak-Kovacina.

PUBLICATION DETAILS

JOURNAL

Advanced Materials Technologies

YEAR

2026

INSTITUTIONS

University of New South Wales, Tyree Foundation Institute of Health Engineering

COUNTRIES

Australia

INSTRUMENT USED

MicroTester

TESTING METHODS

Compression TestingHydrated and Temperature Controlled TestingMicro-Mechanical Testing

RESEARCH APPLICATIONS

Drug Screening & Drug Delivery MechanicsHydrogel Mechanical TestingInjectable & Regenerative BiomaterialsOrganoid and Tissue Mimetic Systems

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