Fabrication of Microstructured Hydrogels via Dehydration for On-Demand Applications

Area of Science:

• Materials Science
• Polymer Chemistry
• Microfabrication

Background:

• Microstructured hydrogels are valuable in engineering, but cost-effective, controllable fabrication remains a challenge.
• Existing methods like molding and 3D printing have limitations in cost and precision.
• Developing accessible fabrication techniques is crucial for advancing hydrogel applications.

Purpose of the Study:

• To present a novel, low-cost method for fabricating microstructured hydrogels.
• To demonstrate high controllability over microstructure shape and profile.
• To showcase the versatility of the fabricated hydrogels in diverse engineering fields.

Main Methods:

• Utilized dehydration of double network hydrogels.
• Employed mask-assisted photopolymerization with common acrylate monomers.
• Varied exposure time and masks to control microstructure features.
• Fabricated both convex and concave microstructures by altering monomers and masks.

Main Results:

• Achieved precise control over hydrogel microstructure shape and profile.
• Successfully fabricated convex and concave microstructures.
• Demonstrated the hydrogel's utility as a mold for polydimethylsiloxane microlens arrays.
• Created anisotropic wetting surfaces and open microfluidic devices with rapid directional superspreading.

Conclusions:

• The presented dehydration and photopolymerization method offers a controllable and low-cost approach to microstructured hydrogel fabrication.
• The technique is versatile, enabling applications in microlens arrays, anisotropic wetting surfaces, and microfluidic devices.
• This method overcomes limitations of existing techniques, paving the way for broader hydrogel utilization in engineering.