High‐Performance Organohydrogel Artificial Muscle with Compartmentalized Anisotropic Actuation Under Microdomain Confinement

Abstract

Current hydrogel actuators mostly suffer from weak actuation strength and low responsive speed owing to their solvent diffusion‐induced volume change mechanism. Here a skeletal muscle‐inspired organohydrogel actuator is reported in which solvents are confined in hydrophobic microdomains. Organohydrogel actuator is driven by compartmentalized directional network deformation instead of volume change, avoiding the limitations that originate from solvent diffusion. Organohydrogel actuator has an actuation frequency of 0.11 Hz, 110 times that of traditional solvent diffusion‐driven hydrogel actuators (<10−3 Hz), and can lift more than 85 times their own weight. This design achieves the combination of high responsive speed, high actuation strength, and large material size, proposing a strategy to fabricate hydrogel actuators comparable with skeletal muscle performance.

Bioinspired Multiphase Gels Using Spatial Confinement Strategy

“…26,52 Zhang et al have developed an organohydrogel actuator mimicking the structure of skeletal muscle (Figure 6). 12 First, a poly(N-isopropylacrylamide) (PNIPAM) hydrogel was fabricated, stretched, fixed, and dried, orientating the polymer network by mechanical force. Monomer LMA, cross-linker EGDMA, and photoinitiator DEOP were solved in ethanol and incorporated into the dried PNIPAM matrix by swelling.…”

“…This anisotropic structure permits multiple muscle fibers to gather their actuation force in the same direction, thus maximizing the total output force of skeletal muscle. , As a comparison, most hydrogel actuators are driven by osmotic pressure . Hydrogels characterized by high water content are commonly correlated with reduced strength; meanwhile, the sluggish solvent process leads to slow actuation speed. , The structure and actuation mechanism of human skeletal muscle have provided valuable guidance for the design of functional actuation materials. Gel actuators can also exhibit remarkable high actuation speed and strength when replicating the structure of muscle, which means they are composed of parallel aligned actuation polymer fibers and a surrounding confinement oleophilic network.…”

A Skin‐Inspired Multifunctional Conductive Hydrogel with High Stretchable, Adhesive, Healable, and Decomposable Properties for Highly Sensitive Dual‐Sensing of Temperature and Strain

“…[1] The skin has excellent physicochemical properties, such as strong mechanical DOI: 10.1002/smtd.202300749 properties, self-healing properties and decomposition. [2][3][4][5] Excellent mechanical properties give the skin flexibility and stretchability, preventing the body from mechanical damage (such as friction, extrusion). When the skin is damaged, it can heal and recover within a few days, and the same functions can be achieved after self-healing.…”

Oxygen-co-Thermal Driver for Constructing Integrated Anisotropic Hydrogels with Programmable Shape Deformation, Superior Self-Healing, and Mechanical Performance

“…Stimulus-responsive anisotropic hydrogels are uniquely shape-deformable, which makes them widely used in flexible electronics, , smart actuators, , drug delivery, , soft robotics, , artificial muscles, , etc. Notably, the asymmetric structure is the fundamental element that drives the hydrogel to transform external stimuli into deformation or motion. , The gradient structure, as a common asymmetric structure, is widely used in hydrogel actuators currently due to its integrated nature and fewer steps in the preparation process.…”