An iodine-driven muscle-mimicking self-resetting bilayer hydrogel actuator

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Muscle-mimicking hydrogels often lack the self-resetting mechanism of natural muscles.
• Existing hydrogel actuators can accumulate errors due to repetitive actuation cycles.
• Natural muscles contract using adenosine triphosphate (ATP) and relax spontaneously upon ATP depletion.

Purpose of the Study:

• To develop a hydrogel actuator with a self-resetting mechanism similar to natural muscles.
• To investigate the I2-responsiveness of poly(ethylene glycol)-based hydrogels for actuation.
• To demonstrate biomimicking functions using the developed actuator.

Main Methods:

• Fabrication of a bilayer hydrogel actuator utilizing I2-responsive poly(ethylene glycol)-based hydrogel.
• Integration of the actuator with a reaction network generating iodine (I2) as an intermediate product.
• Utilizing the spontaneous deformation and recovery of the hydrogel actuator driven by I2 generation and consumption.

Main Results:

• The developed hydrogel actuator exhibits temporary deformation and spontaneous recovery.
• The actuation mechanism closely mimics that of natural muscles.
• The actuator successfully demonstrated several biomimicking functions.

Conclusions:

• The novel hydrogel actuator successfully replicates the self-resetting actuation mechanism of natural muscles.
• This approach offers a promising pathway for creating more accurate and reliable biomimetic actuators.
• The I2-responsive hydrogel system provides a new platform for advanced material design.