Solvent-adaptive hydrogels with lamellar confinement cellular structure for programmable multimodal locomotion.

Area of Science:

• Materials Science
• Soft Robotics
• Polymer Chemistry

Background:

• Biological systems exhibit complex multimodal motion via hierarchical anisotropic structures.
• Artificial soft actuators face limitations in response speed, programmability, and environmental tolerance.
• Existing actuators struggle with precision in structural design and anisotropic hierarchy for advanced locomotion.

Purpose of the Study:

• To fabricate environmentally tolerant and fast-responsive hydrogels with advanced structural features.
• To achieve programmable multi-gait locomotion in hydrogels with precise control over amplitude and directionality.
• To develop soft actuators suitable for operation in harsh solvent environments.

Main Methods:

• Programmed assembly directed confinement polymerization.
• Directional freezing-assisted polymerization within a predesigned anisotropic laminar scaffold.
• Fabrication of hydrogels with lamellar assembly-confined cellular structure and aligned nanopillars.

Main Results:

• The hydrogels demonstrated ultrafast responsiveness and anisotropic deformation under temperature, light, and solvent stimuli.
• Consistent responsive deformation was maintained in all-polarity solvents for over 100 days.
• Photoactive programmable multi-gait locomotion, including crawling, rotation, floating, and swimming, was achieved and precisely regulated.

Conclusions:

• The developed hydrogels possess a hierarchically ordered structure enabling dexterous locomotion.
• These materials exhibit exceptional environmental tolerance and responsiveness, outperforming current soft actuators.
• The hydrogels show significant potential for flexible intelligent actuators in demanding solvent conditions.