Three-Dimensional Printing of Double-Network Hydrogels: Recent Progress, Challenges, and Future Outlook

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Hydrogels are biocompatible, mimicking the extracellular matrix, but often lack mechanical toughness.
• Shaping hydrogels into complex 3D structures is a significant challenge.
• Double-network hydrogels (DN gels) exhibit superior toughness and stretchability, suitable for tissue engineering and soft robotics.

Purpose of the Study:

• To review state-of-the-art technologies for shaping tough and stretchable double-network hydrogels (DN gels).
• To discuss conventional molding, casting, extrusion, and optics-based 3D printing methods for DN gel fabrication.
• To highlight key challenges and future outlooks in 3D shaping of DN gels.

Main Methods:

• Review of conventional molding and casting techniques for DN gel fabrication.
• Analysis of extrusion-based 3D printing methods for creating complex DN gel structures.
• Evaluation of optics-based 3D printing approaches for precise DN gel geometry control.

Main Results:

• Conventional methods are limited to simple shapes, while 3D printing enables complex geometries.
• Extrusion and optics-based 3D printing offer versatile routes for fabricating custom DN gel structures.
• Advancements in 3D printing overcome previous limitations in shaping tough and stretchable hydrogels.

Conclusions:

• 3D printing technologies are revolutionizing the fabrication of complex double-network hydrogel geometries.
• These advancements expand the potential applications of tough and stretchable hydrogels in various fields.
• Further research is needed to address challenges and optimize 3D printing for DN gel applications.