Engineering Tough Supramolecular Hydrogels with Structured Micropillars for Tunable Wetting and Adhesion Properties

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Engineering

Background:

• Soft-lithography is a common technique for microstructuring plastics and elastomers.
• Fabricating high-aspect-ratio microstructures on hydrogels is challenging due to their low mechanical strength and stiffness, hindering demolding.

Purpose of the Study:

• To engineer tough hydrogels capable of forming well-defined microstructures using soft-lithography.
• To leverage temperature-dependent mechanical properties for facile fabrication and tunable surface functionalities.

Main Methods:

• Utilized poly(acrylamide-co-methacrylic acid) hydrogels with temperature-dependent mechanical properties.
• Employed soft-lithography at low temperatures for easy demolding of micro-pillar arrays.
• Investigated shape-memory properties for morphological control of microstructures.

Main Results:

• Achieved fabrication of well-defined micropillar arrays on tough hydrogels via temperature-controlled soft-lithography.
• Demonstrated significant tuning of mechanical properties (Young's modulus from 8.1 MPa to 821.8 MPa) with temperature.
• Showcased tunable wetting and adhesion properties of the hydrogel surfaces, influenced by microstructure geometry and arrangement.

Conclusions:

• Developed a facile strategy for fabricating microstructured surfaces on hydrogels by exploiting tunable viscoelasticity.
• The engineered hydrogels exhibit controllable surface properties and shape-memory effects.
• This approach holds potential for broader applications in biomedical and engineering fields.