Marine Amoebae-Inspired Salting Hydrogels to Reconfigure Anisotropy for Reprogrammable Shape Morphing

Area of Science:

• Materials Science
• Soft Robotics
• Biomimicry

Background:

• Reprogrammable shape morphing is essential for biological movement and survival.
• Asymmetric hydrogel structures are used to mimic biological shape changes but lack post-fabrication tunability.
• Achieving reprogrammable shape morphing in hydrogels presents a significant challenge.

Purpose of the Study:

• To develop a novel strategy for reprogrammable shape morphing in hydrogels.
• To reconfigure the anisotropy of hydrogel soft actuators.
• To mimic the adaptive morphology changes observed in marine organisms.

Main Methods:

• Utilized polyampholyte hydrogels with balanced COO- and N+(CH3)3 groups.
• Swelled hydrogels in an HCl/NaCl solution.
• Transferred swollen hydrogels to water, inducing osmotic swelling followed by spontaneous deswelling due to pH and ion changes.

Main Results:

• Demonstrated a new method for reconfiguring hydrogel anisotropy using a salting strategy.
• Achieved reprogrammable shape morphing in hydrogel soft actuators.
• Hydrogels exhibited adaptive shape changes in response to external salt concentrations and subsequent transfer to water.

Conclusions:

• The developed salting strategy offers a novel approach to hydrogel actuator design.
• This method enables reprogrammable shape morphing by reconfiguring hydrogel anisotropy.
• Opens new avenues for creating adaptable and reconfigurable soft robotic systems.