Autonomous Spatiotemporal Regulation of Reversible Hydrogel Actuators by Chemical Reaction Networks

Area of Science:

• Materials Science
• Chemical Engineering
• Biomimetic Systems

Background:

• Autonomous control of reversible hydrogel movement is difficult.
• Current methods often require external triggers or result in irreversible changes.

Purpose of the Study:

• To achieve autonomous spatiotemporal regulation of reversible hydrogel actuators.
• To develop a system that mimics the self-directed motion observed in biological systems.

Main Methods:

• Utilized thiol-based chemical reaction networks (CRNs) for autonomous control.
• Engineered a bilayer hydrogel actuator with phenylcyanoacrylate Michael acceptors.
• Incorporated autocatalytic thiol production and negative feedback mechanisms (thiol oxidation/acrylamide addition).

Main Results:

• Demonstrated reversible hydrogel swelling and bending triggered by thiol-mediated chemical changes.
• Identified optimal methoxy-substituted acceptors for robust actuation.
• Successfully generated spatiotemporal actuation waves using coupled CRNs in various actuator shapes (linear, flower, hand).

Conclusions:

• Developed a novel system for autonomous, reversible hydrogel actuation.
• Integrated reversible chemistry with spatiotemporal control for biomimetic motion.
• This approach represents a significant advancement toward emulating autonomous movement in synthetic systems.