Stereolithographic 3D Printing for Deterministic Control over Integration in Dual-Material Composites

Area of Science:

• Biomaterials Science
• Materials Engineering
• Tissue Engineering

Background:

• Integrating materials with distinct properties is crucial for advanced applications like tissue engineering.
• Achieving predictable and robust interfaces between soft and stiff hydrogels remains a challenge.

Purpose of the Study:

• To develop a rapid and controllable method for integrating dissimilar hydrogels.
• To leverage grayscale 3D printing for precise control over material integration distances.

Main Methods:

• Utilized grayscale 3D printing to create patterned interfaces in photopolymerizable resins.
• Correlated printing parameters (effective exposure dose) to resin mesh size for controlled diffusion.
• Infilled 3D printed structures with a second hydrogel to achieve programmed integration.

Main Results:

• Demonstrated high-fidelity integration over a defined distance between soft and stiff hydrogels.
• Achieved a 33% increase in strain to failure and eliminated interfacial failure.
• Successfully fabricated a 3D printed construct integrated with living osteoblastic cells.

Conclusions:

• The developed approach enables predictable control over hydrogel integration, crucial for heterogeneous material design.
• This method enhances mechanical properties at material interfaces and reduces failure.
• The technique shows significant promise for applications requiring multi-material integration and cell encapsulation.