Hydrogel Walkers with Electro-Driven Motility for Cargo Transport

Abstract

In this study, soft hydrogel walkers with electro-driven motility for cargo transport have been developed via a facile mould-assisted strategy. The hydrogel walkers consisting of polyanionic poly(2-acrylamido-2-methylpropanesulfonic acid-co-acrylamide) exhibit an arc looper-like shape with two “legs” for walking. The hydrogel walkers can reversibly bend and stretch via repeated “on/off” electro-triggers in electrolyte solution. Based on such bending/stretching behaviors, the hydrogel walkers can move their two “legs” to achieve one-directional walking motion on a rough surface via repeated “on/off” electro-triggering cycles. Moreover, the hydrogel walkers loaded with very heavy cargo also exhibit excellent walking motion for cargo transport. Such hydrogel systems create new opportunities for developing electro-controlled soft systems with simple design/fabrication strategies in the soft robotic field for remote manipulation and transportation.

Spore‐Based Water‐Resistant Water‐Responsive Actuators with High Power Density

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require external stimuli such as high electric fields, or high temperatures and pressures. [7,8] A variety of materials, such as graphene oxide, [9][10][11][12] polymers, [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] liquid crystals, [14,29,30] paper, [31,32] and biologically based materials [6][7][8][33][34][35][36] can serve as hygroscopic actuators. [7,8] A variety of materials, such as graphene oxide, [9][10][11][12] polymers, [13][14][15][16][17][18][19][20][21]

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“…[1,2] These materials can be driven by perturbations to the ambient humidity or with natural fluctuations. These actuators exhibit curling and folding, [10,14,19] walking, [17,21,24,37] gripping, [18] and power generation functions. These actuators exhibit curling and folding, [10,14,19] walking, [17,21,24,37] gripping, [18] and power generation functions.…”

Smart hydrogels: Network design and emerging applications

“…One simple method for accelerating the response dynamics of hydrogels is doping nanoparticles to build a diffusion passage or platform through the cross‐linked polymer networks . For example, the hydrogel composed of polyelectrolyte can possess electro‐sensitive swelling/deswelling or bending/unbending . Some charge groups are restricted by the crosslinked networks in the hydrogel; only the mobile counter ions can move towards the electrodes.…”

“…The smart hydrogels, which exhibit stimuli‐sensitive swelling/deswelling or bending/unbending properties, are able to be used as soft actuators to accomplish the conversion of chemical or physical signals to mechanical force. For example, electro‐responsive polyanionic poly(2‐acrylamido‐2‐methylpropanesulphonic acid‐ co ‐acrylamide) (P(AMPS‐ co ‐AAm)) hydrogel has been prepared with anisotropic networks via a simple mould‐assisted method, which exhibits an arc looper‐like shape with two legs for walking . Such a hydrogel walker can achieve reversible and repeatable bending‐stretching behaviours through repeated on‐off electro‐triggers for transporting cargo …”

Heterogeneous Conductance‐Based Locally Shape‐Morphable Soft Electrothermal Actuator

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appropriate for human-machine interactions and use in wearable devices, as they can handle soft materials and arbitrary shapes. Among them, electrical stimuli provided by electroactive and field-activated polymers such as electro-driven hydrogels [16] and ionic polymer-metal composites (IPMCs) [17] are considered to be the most suited for this purpose. Among them, electrical stimuli provided by electroactive and field-activated polymers such as electro-driven hydrogels [16] and ionic polymer-metal composites (IPMCs) [17] are considered to be the most suited for this purpose.

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