Digital Light Processing 4D Printing of Transparent, Strong, Highly Conductive Hydrogels.

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Hydrogels offer desirable properties like biocompatibility and conductivity.
• Fabricating hydrogels via photopolymerization 3D printing is challenging due to photoinitiator solubility issues.

Purpose of the Study:

• To overcome limitations in 3D printing hydrogels.
• To develop strong, elastic, and ionically conductive hydrogels with complex structures.

Main Methods:

• Synthesized a microemulsion to enable the use of hydrophobic photoinitiators.
• Utilized digital light processing (DLP) 3D printing technology.
• Employed chemical crosslinking and ion coordination for enhanced properties.

Main Results:

• Fabricated transparent hydrogels with high strength (22.9 MPa), elasticity (583%), and ionic conductivity (9.64 S m⁻¹).
• Achieved high-resolution 3D printing of complex structures.
• Demonstrated dual-material 3D printing for packaging hydrogels with elastomers.

Conclusions:

• The developed microemulsion strategy facilitates the 3D printing of high-performance hydrogels.
• The resulting hydrogels are suitable for sensitive wearable sensors monitoring human motion.
• Hydrogel's solvent-induced dehydration and shape memory properties are beneficial for biomedical applications.