Self-Evolving Hierarchical Hydrogel Fibers with Circadian Rhythms and Memory Functions

Area of Science:

• Materials Science
• Biomimetic Engineering
• Soft Robotics

Background:

• Biological systems efficiently transfer matter and energy across hierarchical tissues via specialized transport channels.
• Replicating this simultaneous hierarchical fusion and ultrafast transport in artificial systems remains a significant challenge.

Purpose of the Study:

• To create a multimaterial hydrogel fiber with hierarchical interface fusion and ultrafast selective transport.
• To investigate the unique water transport mechanisms and emergent properties of this artificial system.

Main Methods:

• Spontaneous hierarchical structure formation via in situ ionic cross-linking and molecular shear flow.
• Utilizing aligned cellulose nanocrystals (CNCs) to create angstrom-scale slits for water transport.
• Investigating water transport via Coulomb knock-on and collective motion dynamics.

Main Results:

• Demonstrated spontaneous hierarchical fusion and ultrafast water transport through CNC-based slits.
• Observed Newton's cradle-like water motion and a negative feedback loop within the fiber.
• Exhibited time-space perception, short-term memory, adaptive shape changes, and a 24-h rhythm.

Conclusions:

• The developed hierarchical hydrogel fibers possess neuron-like memristor effects.
• These fibers show significant potential for seamless on-skin and implantable bioelectronic applications.