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The dynamics of a soft particle suspended in a viscous fluid can be changed by the presence of an elastic boundary. Understanding the mechanisms and dynamics of soft–soft surface interactions can provide valuable insights into many important research fields, including biomedical engineering, soft robotics development, and materials science. This work investigates the anomalous transport properties of a soft nanoparticle near a visco-elastic interface, where the particle consists of a polymer assembly in the form of a micelle and the interface is represented by a lipid bilayer membrane. Mesoscopic simulations using a dissipative particle dynamics model are performed to examine the impact of micelle's proximity to the membrane on its Brownian motion. Two different sizes are considered, which correspond to ≈ 10 − 20 n m in physical units. The wavelengths typically seen by the largest micelle fall within the range of wavenumbers where the Helfrich model captures fairly well the bilayer mechanical properties. Several independent simulations allowed us to compute the micelle trajectories during an observation time smaller than the diffusive time scale (whose order of magnitude is similar to the membrane relaxation time of the largest wavelengths), this time scale being hardly accessible by experiments. From the probability density function of the micelle normal position with respect to the membrane, it is observed that the position remains close to the starting position during ≈ 0.05 τ d (where τd corresponds to the diffusion time), which allowed us to compare the negative excess of mean-square displacement (MSD) to existing theories. In that time range, the MSD exhibits different behaviors along parallel and perpendicular directions. When the micelle is sufficiently close to the bilayer (its initial distance from the bilayer equals approximately twice its gyration radius), the micelle motion becomes quickly subdiffusive in the normal direction. Moreover, the temporal evolution of the micelle MSD excess in the perpendicular direction follows that of a nanoparticle near an elastic membrane. However, in the parallel direction, the MSD excess is rather similar to that of a nanoparticle near a liquid interface. [ABSTRACT FROM AUTHOR]

Soft pneumatic robotics have attracted considerable attention in recent years due to their deformation capabilities, which far exceed those of conventional robotics. However, precise control of soft pneumatic actuators remains a challenge due to the lack of model-based control techniques. This work aims to employ a high-precision and low-cost backpropagation (BP) neural network-based model method to control a 3D soft pneumatic actuator. Experiments show that this BP neural network-based model control method performs well in terms of precision, in which the errors of bending angle and deflection angle are within 0.8° and 1.2°, respectively, and the end point position error of the soft actuator is less than 2.5 mm, which is significantly better than traditional modeling methods, demonstrating the application potential of soft robots for high-precision operations. [ABSTRACT FROM AUTHOR]

Robot grippers based on the jamming of granular material have been studied widely in previous years. Recently, also other benefits and challenges of granular material have emerged for robotics. We discuss various functions of granular matter in robotic actuation, sensory processing, locomotion, and manipulation. We also provide a review of the design and methods of robots for moving in or on challenging granular environments. Drawing on the properties of granular material and their potential applications, we propose our unique perspectives and innovative ideas for future research and development in this field. [ABSTRACT FROM AUTHOR]

The emergence of millimeter-scale soft actuators has significantly expanded the potential applications in areas such as search and rescue, drug delivery, and human assistance, due to their high flexibility. Despite these advancements, achieving precise control over the intricate movements of soft crawlers poses a significant challenge. In this study, we have developed an all-optical approach that enables manipulation of propulsive forces by simultaneously modifying the magnitude and direction of friction forces, thereby enabling complex motions of soft actuators. Importantly, the approach is not constrained by specific actuator shapes, and theoretically, any elongated photothermal actuator can be employed. The actuator was designed with an isosceles trapezoid shape, featuring a top width of 2 mm, a bottom width of 4 mm, and a length of 8 mm. Through our manipulation approach, we showcase a proof-of-concept for complex soft robotic motions, including crawling (achieving speeds of up to 2.25 body lengths per minute), turning, avoiding obstacles, handling and transferring objects approximately twice its own weight, and navigating narrow spaces along programmed paths. Our results showcase this all-optical manipulation approach as a promising, yet unexplored tool for the precision and wireless control for the development of advanced soft actuators. [ABSTRACT FROM AUTHOR]

The oscillatory pitch motion at the leading edge of a millimeter‐scale flexible sheet on the water surface can generate undulatory locomotion for swimming, similar to a honeybee vibrating its wings for propulsion. The influence of various parameters on such swimming strategy remains unexplored. This study uses magnetic milliswimmers to probe the propulsion mechanics and impact of different parameters. It is found that this undulatory propulsion is driven by capillary forces and added mass effects related to undulatory waves of the milliswimmers, along with radiation stress stemming from capillary waves at the interface. Modifying the parameters such as actuation frequency, pitch amplitude, bending stiffness, and hydrofoil length alters the body waveform, thus, affecting the propulsion speed and energy efficiency. Although undulatory motion is not a prerequisite for water surface propulsion, optimizing body stiffness to achieve a proper undulatory waveform is crucial for efficient swimming, balancing energy consumption, and speed. The study also reveals that the induced water flow is confined near the water surface, and the flow structures evolve with varying factors. These discoveries advance the understanding of undulatory water surface propulsion and have implications for the optimal design of small‐scale swimming soft robots in the future. [ABSTRACT FROM AUTHOR]

Additive manufacturing technology has fostered its significant application in soft robotics fabrication due to the design freedom and ease of realizing complex geometries. The selection of an appropriate additive manufacturing process (out-of-material extrusion, vat photopolymerization, and powder bed fusion) is vital for the fabrication of soft robotics as the process greatly influences the quality of the part further affecting the functionality and service life. These pneumatically actuated robots in their service life are subjected to fatigue loading and handling of very delicate tasks; thus, the porosity (including pores characterization) and surface roughness are two critical quality parameters which should be considered while choosing the fabrication process. In this study, a three-way decision-making (a multi-criteria decision-making tool) approach is implemented for selecting an appropriate additive manufacturing process for the fabrication of high-quality parts for soft robotics applications. The results (ranking of AM processes) obtained using the proposed approach are compared with the conventional decision-making techniques, namely TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), MOORA (Multi-Objective Optimization by Ratio Analysis), and VIKOR (VIseKriterijumska Optimizacija). The sensitivity analysis carried out in this work also suggests that three-way decision-making is as effective as other MCDM tools and the vat photopolymerization process is the most suitable out of all for fabricating TPU actuators. [ABSTRACT FROM AUTHOR]

Endowing robots with reversible phase transition ability, especially between elastomer and fluid states, can significantly broaden their functionality and applicability. Limited attempts have been made to realize the reversible elastomer–fluid transition. Existing phase transition materials in robotics have over‐hard (≈4 GPa) or over‐soft (≈4 kPa) stiffness in the solid states, which should be further investigated to perform more compliant motions. To address these challenges, a reversible elastomer–fluid transition mechanism enabled by magnetically induced hot melt materials (MIMMs) is presented. The transition principle is explained and material characterizations are conducted. MIMMs‐based metamorphosic robots endow self‐metamorphosing abilities, such as self‐healing, spatial reshaping, self‐division/assembly, and additive manufacturability. When interacting with external environments, MIMMs‐based robots can perform further multifunctional abilities, such as collaborations for structure repairs, swimming by symbiosis with external objects, flowing through a narrow terrain by transiting to fluid, and working with elastomeric structures for stiffness‐variable fluid soft actuators. The proposed elastomer–fluid transitions open a new path for robots to generate more flexible and metamorphosic motions, thereby addressing the cross‐phase transformation challenges that soft robots face. [ABSTRACT FROM AUTHOR]

Although recent years have seen considerable interest in stimuli‐responsive hydrogels, their strict preparation conditions and narrow applicability limit their use as diverse sensors and soft robots. Herein, a versatile Agar‐Zwirrions hybrid hydrogel actuator (Agar/PSBMA) integrated with simultaneous temperature self‐sensing and wide‐range electrical response is developed. To prepare the Agar/PSBMA hydrogel, a simple and controllable preforming post‐enhancing and mechanical pressing method is used by introducing zwitterions materials into a temperature‐sensitive Agar matrix. Owing to the design, the compact multiplex complementary structure generated by this method and the materials can facilitate the improvement of flexibility, stretchability, and toughness while providing mechanical dissipation and adhesion properties. Importantly, the visible detected temperature self‐sensing ability during 10–40 °C, and quick and wide‐range bending responses of both high‐voltage and low‐voltage electric fields make it unique over other actuators. Furthermore, the electrical response behavior of the hydrogel is found to be impacted by mechanical characteristics and charge polarization based on the finite element Abaqus simulations analysis. The prepared versatile hydrogels show the potential for applications as soft robotics and controlled transportation of adhered substances while simultaneously monitoring their working temperature, which expands the response range of hydrogel actuators and broadens the scope of application. [ABSTRACT FROM AUTHOR]

Liquid crystal elastomers (LCEs) with photo‐responsive properties, typically driven by either photochemical or photothermal mechanisms, have found extensive applications as, for example, actuators in soft robots. However, intricate temperature‐dependent viscoelasticity of LCEs poses a challenge, leading to a notable gap in the domain of dynamic models for photothermal‐responsive LCE (PTR‐LCE) fibers. Here, a fundamental framework is proposed for accurate modeling and real‐time simulations of PTR‐LCE fiber dynamics. The PTR‐LCE fiber is described as a one‐dimensional (1D) string model that decomposes the fiber deformation into active and passive parts, which are characterized by an order parameter and a temperature‐dependent linear viscoelasticity model, respectively. Then, independent experimental measurements of model parameters are conducted, and a numerical algorithm is developed to solve the model, which is validated for convergence, time efficiency, and accuracy. Finally, the model is employed to simulate both open‐loop and Proportional‐Integral‐Derivative (PID) control of actuators made of PTR‐LCE fibers. The results confirm the advantages of this model over previous models. This work not only reveals the physical mechanisms underlying the PTR‐LCE fiber dynamic behaviors but also provides inspirations for more efficient and precise soft robotic applications. [ABSTRACT FROM AUTHOR]

The study of bio-inspired structures and their reproduction has always fascinated humans. The advent of soft robotics, thanks to soft materials, has enabled considerable progress in this field. Over the years, polyps, worms, cockroaches, jellyfish, and multiple anthropomorphic structures such as hands or limbs have been reproduced. These structures have often been used for gripping and handling delicate objects or those with complex unknown a priori shapes. Several studies have also been conducted on grippers inspired by the seahorse tail. In this paper, a novel biomimetic soft pneumatic actuator inspired by the tail of the seahorse Hippocampus reidi is presented. The actuator has been developed to make a leg to sustain a multi-legged robot. The prototyping of the actuator was possible by combining a 3D-printed reinforcement in thermoplastic polyurethane, mimicking the skeletal apparatus, within a silicone rubber structure, replicating the functions of the external epithelial tissue. The latter has an internal channel for pneumatic actuation that acts as the inner muscle. The study on the anatomy and kinematic behaviour of the seahorse tail suggested the mechanical design of the actuator. Through a test campaign, the actuator prototype was characterized by isotonic tests with an external null load, isometric tests, and activation/deactivation times. Specifically, the full actuator distension of 154.5 mm occurs at 1.8 bar, exerting a maximum force of 11.9 N, with an activation and deactivation time of 74.9 and 94.5 ms, respectively. [ABSTRACT FROM AUTHOR]

Coordination of functions in multi‐body or multi‐component systems requires communication among its parts and is a prerequisite for achieving complex tasks. While electromagnetic (network) communication provides a key ingredient for modern robotics, its molecular equivalent is largely missing for soft robots. With advancements in programmed cargo release, DNA strand‐displacement reactions, enzymatic cascades, and genetic circuits, budding solutions to such chemical network communication have emerged with the potential to drive function in soft machines. In order for such chemical communication to be useful, however, new control concepts, (orthogonal) communication protocols, and molecular solutions should be found. Herein, we provide a critical perspective on the current state‐of‐the‐art chemical communication and identify key challenges towards autonomous soft materials, including signal processing, dealing with noise, switching signaling modalities, and limitations in time and length scales that determine material design. Building on an emerging body of examples, we illustrate gaps, synergies, and new concepts that may provide possible solutions to achieve standardized and reliable molecular information exchange for regulating (soft) robotic function. [ABSTRACT FROM AUTHOR]

Hydrogels comprise of a group of crosslinked hydrophilic polymeric materials which are capable of absorbing and holding large quantities of water in their three-dimensional network structure without undergoing dissolution. More importantly, the ability of 'smart' hydrogels to respond to certain environmental changes e.g. pH, heat, light, magnetic field, biomolecules have set them apart as a unique class of materials. A combination of several such useful and unique properties have resulted in a tremendous progress toward development of advanced hydrogel-based materials, as is evident from an explosive amount of research publications available in this area over the last few decades. Owing particularly to their biocompatibility and biodegradability, hydrogels have become a material of prime importance in context to a wide range of applications starting from simple contact lenses to more complex ones e.g. in tissue repair, drug delivery, sensors, 3D bioprinting, soft robotics and agriculture. This review includes i) an overview of hydrogels and its classifications based on source, structure, crosslinking mechanism and stimuli responsiveness, ii) detailed discussion on some of the most advanced research works being carried out in the field over the last few years in context to few smart applications that have become the need of the hour, particularly in the domain of biomedical applications. [ABSTRACT FROM AUTHOR]

A Dielectric Elastomer Actuator (DEA) consists of electrodes with a dielectric layer between them. By controlling the design of the electrodes, voltage, and frequency, the operating range and speed of the DEA can be adjusted. These DEAs find applications in biomimetic robots, artificial muscles, and similar fields. When voltage is applied to the DEA, the dielectric layer undergoes compression and expansion due to electrostatic forces, which can lead to electrical breakdown. This phenomenon is closely related to the performance and lifespan of the DEA. To enhance stability and improve dielectric properties, a DEA Reservoir layer is introduced. Here, stability refers to the ability of the DEA to perform its functions even as the applied voltage increases. The Reservoir layer delays electrical breakdown and enhances stability due to its enhanced thickness. The proposed DEA in this paper is composed of a Reservoir layer and electrode layer. The Reservoir layer is placed between the electrode layers and is independently configured, not subjected to applied voltage like the electrode layers. The performance of the DEA was evaluated by varying the number of polymer layers in the Reservoir and electrode designs. Introducing the Reservoir layer improved the dielectric properties of the DEA and delayed electrical breakdown. Increasing the dielectric constant through the DEA Reservoir can enhance output characteristics in response to electrical signals. This approach can be utilized in various applications in wearable devices, artificial muscles, and other fields. [ABSTRACT FROM AUTHOR]

Soft pneumatic actuators (SPAs) hold great promise for simple and effective actuation of soft robots. Multi‐degree‐of‐freedom SPAs are highly desired as they enable diverse motion forms and improve possibility for soft robots to navigate challenging environments and perform complex tasks. Herein, this study proposes two novel origami‐based SPAs (O‐SPAs), namely the Flasher origami‐inspired SPA (FO‐SPA) and the Kresling origami‐inspired SPA (KO‐SPA), which are fabricated entirely from soft silicone without any rigid supports. A finite element model is developed to predict the deformation behavior of O‐SPAs and the deformability and dynamic response of O‐SPAs are characterized through performance tests. Simulation experiments are carried out to investigate the impact of different structural parameters on their performance. These O‐SPAs are highly sensitive to low negative pressure, exhibiting 80% of maximum deformation at −4 kPa. Based on the Flasher and Kresling origami pattern, the actuators are capable of generating compound motions including contraction, twisting, and radial motions. These motions can be used as "building blocks" for the rapid reconfiguration of various soft robots. The study has successfully enriched the types of existing SPAs by providing important multiple motions through origami, with great potential to facilitate the rapid and low‐cost design of soft robots. [ABSTRACT FROM AUTHOR]

Snap-through instabilities in single and interconnected dielectric elastomer actuators have demonstrated their potential in enabling many functionalities such as large deformation, high-speed actuation, and enhanced flowrates in fluid pumps. However, the nonlinear nature of dielectric elastomers and the complex interplay of mechanics in interconnected inflated actuators, make the modeling of such systems challenging. In this paper, we present a methodology to analytically model the instabilities in a system of three interconnected homogeneous spherical dielectric elastomer actuators through graphical and numerical approaches. The simulation results reveal the presence of a locus of initial stable states that the interconnected actuators can achieve at zero voltage. In specific loading conditions, the system exhibits multiple stable states which can be cyclically transitioned between by selectively applying voltage to specific actuators. In other conditions, the system may undergo two successive instabilities when the voltage applied to a single actuator in the system is increased monotonically. These results retrieve existing experimental results theoretically for the first time and identify a new behavior of cascading instabilities in inflated dielectric elastomer actuators. We hope this work will pave the way for programmable design of multistable systems to unravel new capabilities in dielectric elastomer actuators and soft robotics. [ABSTRACT FROM AUTHOR]

Existing studies on wrinkling, an instability phenomenon commonly observed on electro-active polymers (EAP), have largely ignored the unequal-biaxial taut states, focusing instead on the equal-biaxial deformations of such a material class. EAP-based soft actuators, primarily used in soft robotics, frequently exhibit a variety of instabilities, which may adversely affect their functioning and trigger device failure. Conversely, wrinkles can be utilized proactively in specific applications that necessitate an intentional transformation in surface morphology along with functional particle reinforcement on EAP composites. The dielectric elastomer is a promising EAP material class for the same, often filled with functional particles to improve its electromechanical performance. This paper theoretically develops a continuum physics-based unequal-biaxial deformation model incorporating the classical tension field theory to predict the thresholds on the taut domains in the plane of principal stretches. The model solution ties an unanswered ideal remark on the deviations of taut states with the biaxiality ratio of unequal-biaxially deformed wrinkle appearance in EAP composites. The proposed model solution may aid in designing next-generation soft robotic systems by offering guidelines for the wrinkling control of EAP composites. [ABSTRACT FROM AUTHOR]

Fiber composite materials exhibit exceptional specific stiffness and strength compared to traditional engineering materials. Nevertheless, automating the handling of limp flexible materials like fabrics remains a challenging process, often relying on multi-stage manual operations for hand layups. In this study, carbon fabric properties were initially characterized through standard experiments to develop and calibrate a finite element (FE) model. The FE model was subsequently validated against real-world pick-and-place tests involving soft robotic grippers. The validation results demonstrated a high correlation between the FE model and experiments, achieving an average accuracy of 97.2% for fabric projected area and 84.6% for fabric vertices' displacement. Additionally, the FE model was used to design, evaluate, and optimize alternative automation strategies. It was discovered that a convex surface improved fabric projection area and placement accuracy by 5.9% and 1.9%, respectively, compared to a concave surface with the same curvature radius. Larger concave surfaces contributed to increased projected area and placement accuracy as well. Longitudinal pick-and-place operations also enhanced the projection area and placement accuracy compared to transverse handling processes. Achieving successful fabric pick-and-place operations necessitates a comprehensive system's approach, considering the interaction between grippers, fabric, and mold surface. The FE model developed in this study will be further employed by the current research team in designing innovative compliant grippers tailored to complex mold surface geometries and specific fabric material requirements. The presented FE model offers valuable insights and paves the way for rapid, efficient, cost-effective, and secure implementation of automation solutions for handling limp flexible materials. [ABSTRACT FROM AUTHOR]

Improving the energy efficiency of robots remains a crucial challenge in soft robotics, with energy harvesting emerging as a promising approach to address it. This study presents a functional soft robotic composite called OPV-DEA, which integrates flexible organic photovoltaic (OPV) and dielectric elastomer actuator (DEA). The composite can simultaneously generate electrostatic bending actuation and harvest energy from external lights. Owing to its simplicity and inherent flexibility, the OPV-DEA is poised to function as a fundamental building block for soft robots. This study aimed to validate this concept by initially establishing the fabrication process of OPV-DEA. Subsequently, experimental samples are fabricated and characterized. The results show that the samples exhibit a voltage-controllable bending actuation of up to 15.6° and harvested power output of 1.35 mW under an incident power irradiance of 11.7 mW/cm2. These performances remain consistent even after 1000 actuation cycles. Finally, to demonstrate the feasibility of soft robotic applications, an untethered swimming robot equipped with two OPV-DEAs is fabricated and tested. The robot demonstrates swimming at a speed of 21.7 mm/s. The power consumption of the robot is dominated by a high-voltage DC-DC converter, with a value approximately 1.5 W. As a result, the on-board OPVs cannot supply the necessary energy during locomotion simultaneously. Instead, they contribute to the overall system by charging a battery used for the controller on board. Nevertheless, these findings suggest that the OPV-DEA could pave the way for the development of an unprecedented range of functional soft robots. [ABSTRACT FROM AUTHOR]

Self‐oscillating gel systems exhibiting an expanded operating temperature and accompanying functional adaptability are showcased. The developed system contains nonthermoresponsive main‐monomers, such as N,N‐dimethylacrylamide (DMAAm) or 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) or acrylamide (AAm) or 3‐(methacryloylamino)propyl trimethylammonium chloride (MAPTAC). The gels volumetrically self‐oscillate within the range of the conventional (20.0 °C) and extended (27.0 and 36.5 °C) temperatures. Moreover, the gels successfully adapt to the environmental changes; they beat faster and smaller as the temperature increases. The period and amplitude are also controlled by tuning the amount of main‐monomers and N‐(3‐aminopropyl) acrylamide. Furthermore, the record amplitude in the bulk gel system consisting of polymer strand and cross‐linker at 36.5 °C is achieved (≈10.8%). The study shows new self‐oscillation systems composed of unprecedented combinations of materials, giving the community a robust material‐based insight for developing more life‐like autonomous biomimetic soft robots with various operating temperatures and beyond. [ABSTRACT FROM AUTHOR]

Flexible and stretchable microdevices incorporate highly deformable structures, facilitating precise functionality at the micro- and millimetre scale. Flexible microdevices have showcased extensive utility in the fields of biomedicine, microfluidics, and soft robotics. Actuation plays a critical role in transforming energy between different forms, ensuring the effective operation of devices. However, when it comes to actuating flexible microdevices at the small millimetre or even microscale, translating actuation mechanisms from conventional rigid large-scale devices is not straightforward. The recent development of actuation mechanisms leverages the benefits of device flexibility, particularly in transforming conventional actuation concepts into more efficient approaches for flexible devices. Despite many reviews on soft robotics, flexible electronics, and flexible microfluidics, a specific and systematic review of the actuation mechanisms for flexible and stretchable microdevices is still lacking. Therefore, the present review aims to address this gap by providing a comprehensive overview of state-of-the-art actuation mechanisms for flexible and stretchable microdevices. We elaborate on the different actuation mechanisms based on fluid pressure, electric, magnetic, mechanical, and chemical sources, thoroughly examining and comparing the structure designs, characteristics, performance, advantages, and drawbacks of these diverse actuation mechanisms. Furthermore, the review explores the pivotal role of materials and fabrication techniques in the development of flexible and stretchable microdevices. Finally, we summarise the applications of these devices in biomedicine and soft robotics and provide perspectives on current and future research. [ABSTRACT FROM AUTHOR]

Polymer-based actuators have gained extensive attention owing to their potential applications in aerospace, soft robotics, etc. However, poor mechanical properties, the inability of multi-stimuli response and programmable deformation, and the costly fabrication procedure have significantly hindered their practical application. Herein, these issues are overcome via a simple and scalable one-step molding method. The actuator is fabricated by hot-pressing commercial unidirectional carbon fiber/epoxy prepregs with a commodity PC membrane. Notable CTE differences between the CF and PC layers endow the bilayer actuator with fast and reliable actuation deformation. Benefiting from the high strength of CF, the actuator exhibits excellent mechanical performance. Moreover, the anisotropy of CF endows the actuator with design flexibility. Furthermore, the multifunction of CF makes the actuator capable of responding to thermal, optical, and electrical stimulation simultaneously. Based on the bilayer actuator, we successfully fabricated intelligent devices such as light-driven biomimetic flowers, intelligent grippers, and gesture-simulating apparatuses, which further validate the programmability and multi-stimuli response characteristics of this actuator. Strikingly, the prepared gripper possesses a grasping capacity approximately 31.2 times its own weight. It is thus believed that the concept presented paves the way for building next-generation robust robotics. [ABSTRACT FROM AUTHOR]

The flexibility and adaptability of soft robots enable them to perform various tasks in changing environments, such as flower picking, fruit harvesting, in vivo targeted treatment, and information feedback. However, these fulfilled functions are discrepant, based on the varied working environments, driving methods, and materials. To further understand the working principle and research emphasis of soft robots, this paper summarized the current research status of soft robots from the aspects of actuating methods (e.g., humidity, temperature, PH, electricity, pressure, magnetic field, light, biological, and hybrid drive), materials (like hydrogels, shape-memory materials, and other flexible materials) and application areas (camouflage, medical devices, electrical equipment, and grippers, etc.). Finally, we provided some opinions on the technical difficulties and challenges of soft robots to comprehensively comprehend soft robots, lucubrate their applications, and improve the quality of our lives. [ABSTRACT FROM AUTHOR]

Suction is a highly evolved biological adhesion strategy for soft-body organisms to achieve strong grasping on various objects. Biological suckers can adaptively attach to dry complex surfaces such as rocks and shells, which are extremely challenging for current artificial suction cups. Although the adaptive suction of biological suckers is believed to be the result of their soft body's mechanical deformation, some studies imply that in-sucker mucus secretion may be another critical factor in helping attach to complex surfaces, thanks to its high viscosity. Inspired by the combined action of biological suckers' soft bodies and mucus secretion, we propose a multiscale suction mechanism which successfully achieves strong adaptive suction on dry complex surfaces which are both highly curved and rough, such as a stone. The proposed multiscale suction mechanism is an organic combination of mechanical conformation and regulated water seal. Multilayer soft materials first generate a rough mechanical conformation to the substrate, reducing leaking apertures to micrometres (~10 μm). The remaining micron-sized apertures are then sealed by regulated water secretion from an artificial fluidic system based on the physical model, thereby the suction cup achieves long suction longevity on complex surfaces but minimal overflow. We discuss its physical principles and demonstrate its practical application as a robotic gripper on a wide range of complex dry surfaces. We believe the presented multiscale adaptive suction mechanism is a powerful unique adaptive suction strategy which may be instrumental in the development of versatile soft adhesion. [ABSTRACT FROM AUTHOR]

Smart hydrogels responsive to external stimuli are promising for various applications such as soft robotics and smart devices. High mechanical strength and fast response rate are particularly important for the construction of hydrogel actuators. Herein, tough hydrogels with rapid response rates are synthesized using vinyl‐functionalized poly(N‐isopropylacrylamide) (PNIPAM) microgels as macro‐crosslinkers and N‐isopropylacrylamide as monomers. The compression strength of the obtained PNIPAM hydrogels is up to 7.13 MPa. The response rate of the microgel‐crosslinked hydrogels is significantly enhanced compared with conventional chemically crosslinked PNIPAM hydrogels. The mechanical strength and response rate of hydrogels can be adjusted by varying the proportion of monomers and crosslinkers. The lower critical solution temperature (LCST) of the PNIPAM hydrogels could be tuned by copolymerizing with ionic monomer sodium methacrylate. Thermo‐responsive bilayer hydrogels are fabricated using PINPAM hydrogels with different LCSTs via a layer‐by‐layer method. The thermo‐responsive fast swelling and shrinking properties of the two layers endow the bilayer hydrogel with anisotropic structures and asymmetric response characteristics, allowing the hydrogel to respond rapidly. The bilayer hydrogels are fabricated into clamps to grab small objects and flowers that mimicked the closure of petals, and it shows great application prospects in the field of actuators. [ABSTRACT FROM AUTHOR]

Soft pneumatic robotics are designed for safe and compliant interaction with the environment or humans. However, the pneumatic systems used for actuation and protection are still relatively bulky and rely on rigid components such as solenoid valves and pressure regulators. This study presents the design and analysis of soft fibrous valves (SFVs) with internal tiny channels and external helical structures, which could be used in soft pneumatic systems. Made from soft material, SFVs demonstrate unique capabilities in controlling pressure by partial expansion under specific pressure. Three types of SFVs are designed: 1) SFV‐C is designed to protect soft pneumatic actuators by cutting off airflow under excessive pressure; 2) SFV‐M maintains pressure in actuators when the input pressure abruptly drops, preventing potential damage to the operated object; 3) SFV‐O produces oscillating pressure output without electronic control supplied by constant pressure source. Theoretical modeling and experimental validations are conducted to investigate the performance of the SFVs under various stretching, twisting, and pressure conditions. Furthermore, fully flexible SFVs are designed to enhance their compliance and resistance to external impacts. Overall, the SFVs offer promising solutions for pressure control and protection in soft pneumatic systems, enabling safer and more effective operations in various scenarios. [ABSTRACT FROM AUTHOR]

In recent studies concerning walking robots, there has been a notable emphasis on investigating tribological phenomena and elucidating the role of capillary forces in tangential resistance. However, majority of these investigations have been restricted to specific geometric shapes, primarily spherical domes. In this research, we propose a novel approach based on the finite element method to address broader challenge of wet adhesion applicable to objects of various shapes. Additionally, we investigate the role of distributed domes on a soft foot in quantifying the tangential capillary force, which plays a crucial role in enhancing the performance of walking robots on wet surfaces. Through the optimization application, we identify that our designed foot (measuring 20 mm × 14 mm, comprising 78 domes with a radius of 0.5 mm and a distance of 1.5 mm between the two nearest domes) maximizes the value of the tangential capillary force. Moreover, we develop a finite element method using the Simulation Open Framework Architecture (SOFA) to model the interaction between wet liquid on a solid object's curved surface, enabling the calculation of wet adhesion force and capillary forces. Finally, to demonstrate the effectiveness of our proposed morphology-changeable soft pads foot, we conduct a presented a demonstration of a hexapod robot walking on different dry/wet condition of the surface. The obtained results are expected to pave a way to morphological design of soft pads for facilitating locomotion in various conditions. Supplementary video URL: [ABSTRACT FROM AUTHOR]

Camouflage skin holds immense potential for a variety of advanced applications, such as artificial intelligence, soft robotics, and flexible/wearable electronics. Currently, most existing materials for constructing camouflage skin are mainly based on inorganic materials with an inverse opal scaffold, which significantly limits their further development because of the poor mechanical properties and environmental instability. Inspired by rana slvaticas, a new type of camouflage skin based on one‐dimentional (1D) photonic crystal (PC) gel is designed and synthesized, which combines the advantages of 1D PC structures with 3D flexible gels in a single skin device. Taking advantage of the unique structures, the resulting camouflage skins demonstrated attractive properties, including excellent mechanical performance, self‐adaptive camouflage capabilities, and long‐term stability in ambient conditions. Specifically, the camouflage skin can quickly recognize and match the background by modulating the optical signals of external stimuli. The synergistic effect of the glycerol, the dodecyl glycerol itaconate (DGI), and the nano‐space structures altogether contribute to the outstanding long‐term environmental stability of the camouflage skin. Overall, by combining the bio‐inspired concept and molecular engineering strategy, camouflage skin based on PC gels is synthesized, which greatly enriched the application and development in the smart skins field. [ABSTRACT FROM AUTHOR]

Soft robots have recently attracted increasing interest due to their advantages in durability, flexibility, and deformability, which enable them to adapt to unstructured environments and perform various complex tasks. Perception is crucial for soft robots. To better mimic biological systems, sensors need to be integrated into soft robotic systems to obtain both proprioceptive and external perception for effective usage. This review summarizes the latest advancements in flexible sensing feedback technologies for soft robotic applications. It begins with an introduction to the development of various flexible sensors for soft robots, followed by an in‐depth exploration of smart materials and advanced manufacturing methods. A detailed description of flexible sensing modalities and methodologies is also included in the review to illustrate the continuous breakthrough of the technology. In addition, the applications of soft robots based on these advanced sensing technologies are concluded as well. The challenges of flexible sensing technologies for soft robots and promising solutions are finally discussed and analyzed to provide a prospect for future development. By examining the recent advances in intelligent flexible sensing technologies, this review is dedicated to highlighting the potential of soft robotics and motivating innovation within the field. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the concept of the Fluid Jacobian, which provides a description of the power transmission that operates between the fluid and mechanical domains in soft robotic systems. It can be understood as a generalization of the traditional kinematic Jacobian that relates the joint space torques and velocities to the task space forces and velocities of a robot. In a similar way, the Fluid Jacobian relates fluid pressure to task space forces and fluid flow to task space velocities. In addition, the Fluid Jacobian can also be regarded as a generalization of the piston cross-sectional area in a fluid-driven cylinder that extends to complex geometries and multiple dimensions. In the following, we present a theoretical derivation of this framework, focus on important special cases, and illustrate the meaning and practical applicability of the Fluid Jacobian in four brief examples. [ABSTRACT FROM AUTHOR]

Helical structures of liquid crystal elastomers (LCEs) hold promise in soft robotics for self‐regulated rolling motions. The understanding of their motion paths and potentials for terrain exploration remains limited. This study introduces a self‐adjusting, lateral‐rolling soft robot inspired by sidewinder snakes. The spring‐like LCE helical filaments (HFs) autonomously respond to thermal cues, demonstrating dynamic and sustainable locomotion with adaptive rolling along non‐linear paths. By fine‐tuning the diameter, pitch, and modulus of the LCE HFs, and the environmental temperature, the movements of the LCE HFs, allowing for exploration of diverse terrains over a 600 cm2 area within a few minutes, can be programmed. LCE HFs are showcased to navigate through over nine obstacles, including maze escaping, terrain exploration, target hunting, and successfully surmounting staircases through adaptable rolling. [ABSTRACT FROM AUTHOR]

Fluidic logic circuits simplify system design for soft robotics by eliminating bulky components while enabling operation in a range of hostile environments that are incompatible with electronics but at the expense of limited computational capabilities and response times on the order of seconds. This paper presents a four-terminal fluidic transistor optimized for fast switching times, reduced component count, low unit cost, and high reproducibility to achieve complex fluidic control circuits while maintaining flow rates of liters per minute. A ring oscillator using three fluidic transistors achieves oscillation frequencies up to a kilohertz with full signal propagation, tolerating billions of cycles without failure. Fundamental processor circuits like a full adder and a 3-bit analog-to-digital converter require just seven transistors each. A decode circuit drives a high-resolution soft haptic display with refresh times below the human perception threshold for latency, and an electronics-free control circuit performs closed-loop position control of a pneumatic actuator with disturbance rejection, demonstrating the value across domains. [ABSTRACT FROM AUTHOR]

Biological agents have bodies that are composed mostly of soft tissue. Researchers have resorted to soft bodies to investigate Artificial Life (ALife)-related questions; similarly, a new era of soft-bodied robots has just begun. Nevertheless, because of their infinite degrees of freedom, soft bodies pose unique challenges in terms of simulation, control, and optimization. Herein I propose a novel soft-bodied agents formalism, namely, pressure-based soft agents (PSAs): spring-mass membranes containing a pressurized medium. Pressure endows the agents with structure, while springs and masses simulate softness and allow the agents to assume a large gamut of shapes. PSAs actuate both locally, by changing the resting lengths of springs, and globally, by modulating global pressure. I optimize the controller of PSAs for a locomotion task on hilly terrain, an escape task from a cage, and an object manipulation task. The results suggest that PSAs are indeed effective at the tasks, especially those requiring a shape change. I envision PSAs as playing a role in modeling soft-bodied agents, such as soft robots and biological cells. [ABSTRACT FROM AUTHOR]

Soft robotics is closely related to embodied intelligence in the joint exploration of the means to achieve more natural and effective robotic behaviors via physical forms and intelligent interactions. Embodied intelligence emphasizes that intelligence is affected by the synergy of the brain, body, and environment, focusing on the interaction between agents and the environment. Under this framework, the design and control strategies of soft robotics depend on their physical forms and material properties, as well as algorithms and data processing, which enable them to interact with the environment in a natural and adaptable manner. At present, embodied intelligence has comprehensively integrated related research results on the evolution, learning, perception, decision making in the field of intelligent algorithms, as well as on the behaviors and controls in the field of robotics. From this perspective, the relevant branches of the embodied intelligence in the context of soft robotics were studied, covering the computation of embodied morphology; the evolution of embodied AI; and the perception, control, and decision making of soft robotics. Moreover, on this basis, important research progress was summarized, and related scientific problems were discussed. This study can provide a reference for the research of embodied intelligence in the context of soft robotics. [ABSTRACT FROM AUTHOR]

In this paper, a new approach for head camera stabilization of a humanoid robot head is proposed, based on a bio-inspired soft neck. During walking, the sensors located on the humanoid's head (cameras or inertial measurement units) show disturbances caused by the torso inclination changes inherent to this process. This is currently solved by a software correction of the measurement, or by a mechanical correction by motion cancellation. Instead, we propose a novel mechanical correction, based on strategies observed in different animals, by means of a soft neck, which is used to provide more natural and compliant head movements. Since the neck presents a complex kinematic model and nonlinear behavior due to its soft nature, the approach requires a robust control solution. Two different control approaches are addressed: a classical PID controller and a fractional order controller. For the validation of the control approaches, an extensive set of experiments is performed, including real movements of the humanoid, different head loading conditions or transient disturbances. The results show the superiority of the fractional order control approach, which provides higher robustness and performance. [ABSTRACT FROM AUTHOR]

Continuum robots play the role of end effectors in various surgical robots and endoscopic devices. While soft continuum robots (SCRs) have proven advantages such as safety and compliance, more research and development are required to enhance their capability for specific medical scenarios. This research aims at designing a soft robot, considering the concepts of geometric and kinematic similarities. The chosen application is a semi-invasive medical application known as transesophageal echocardiography (TEE). The feasibility of fabrication of a soft endoscopic device derived from the Chorda dorsalis paragon was shown empirically by producing a three-segment pneumatic SCR. The main novelties include bioinspired design, modeling, and a navigation control strategy presented as a novel algorithm to maintain a kinematic similarity between the soft robot and the rigid counterpart. The kinematic model was derived based on the method of transformation matrices, and an algorithm based on a self-organizing map (SOM) network was developed and applied to realize kinematic similarity. The simulation results indicate that the control method forces the soft robot tip to follow the path of the rigid probe within the prescribed distance error (5 mm). The solution provides a soft robot that can surrogate and succeed the traditional rigid counterpart owing to size, workspace, and kinematics. [ABSTRACT FROM AUTHOR]

This article aims at presenting a detailed and practical comparison between three designs of robotic soft fingers for industrial grippers. While the soft finger based on the fin ray effect (FRE) shown here has been proposed long ago, few works in the literature have studied its reliance on the presence of the crossbeams or its precision grasp performance compared to its power grasps. Aiming at addressing these gaps, two novel designs are proposed and compared to FRE fingers in this article. First, the three designs are presented. One of these fingers, named PacomeFlex, embeds changeable grasping modes by relying on two sets of kinematic structures with a bistable stopper design. Then, finite element analyses (FEA) are conducted to simulate power and precision grasps of the three fingers followed by the estimation of the grasp forces produced. These FEA are then used to train neural networks capable of predicting these grasp forces. Finally, the grasp strength and pullout resistance of the fingers are experimentally measured, and experimental results are shown to be in good accordance with the FEA and neural network models. As will also be shown, the PacomeFlex finger introduced in this work provides a noticeably higher performance level than all other fingers with respect to typical metrics in soft grasping. [ABSTRACT FROM AUTHOR]

In organisms, liquid as a continuum intertwines architected components (organs), including nervous, vascular, and musculoskeletal systems. In this regard, spiders exhibit remarkable embodiments where hemolymph, which infuses the animal, simultaneously enables muscle activation and exoskeleton compliance. Previous works on spider‐inspired artificial systems have focused on disentangled aspects, such as pressurization and flexible structures, yet organism‐like liquid‐mediated physical intelligence integrating control, distribution of resources, actuation, and support is still to be demonstrated. Here a spider‐leg‐inspired soft exoskeleton integrating a muscular system is shown, enabled by the contained liquid through hydration for compliance conditioning and charge transport for muscle activation. A two‐photon polymerized 0.8 mm‐diameter exoskeleton is reported that contains an electrolyte solution and is actuated via contraction of an ionic electroactive polymer muscle operated at 0–1 V. The exoskeleton features reversible bending and compliant interaction with natural entities such as anthers, spider webs, and pollen grains. The reported technology demonstrator, which functionally intertwines muscularization, vascularization, and innervation via liquid, supports the development of liquid‐enabled systems based on embodied energy and multi‐material design, particularly for bioinspired soft robotics. [ABSTRACT FROM AUTHOR]

The recent development in smart material-based actuators are composite structures of thin film integrated SMA/PI bimorph in the view of actuator cum sensing in electromechanical systems for medical, robotics, and aerospace application. The purpose of the present work on integrated SMA/PI bimorph is to reveal their ability to perform as actuators and sensors and study on control characteristics for soft robotic, positioning, and valve applications. Vide this research paper, the SMA bimorph actuator [thin film SMA (CuAlNi)/polyimide (Kapton) bimorph] is used as actuator cum sensor for position control. Proposed a Proportional Derivative combined Variable Structure Controller (PD-VSC) to control the displacement by Joule heating actuation in two ways, which are sensor-based control and self-sensing control. From the control characteristics in from of tracking and disturbance rejection, it is concluded that the integrated CuAlNi/Kapton bimorph can be successfully implemented for soft robotic, positioning, and valve applications. [ABSTRACT FROM AUTHOR]

This paper is concerned with the growth-driven shape-programming problem, which involves determining a growth tensor that can produce a deformation on a hyperelastic body reaching a given target shape. We consider the two cases of globally compatible growth, where the growth tensor is a deformation gradient over the undeformed domain, and the incompatible one, which discards such hypothesis. We formulate the problem within the framework of optimal control theory in hyperelasticity. The Hausdorff distance is used to quantify dissimilarities between shapes; the complexity of the actuation is incorporated in the cost functional as well. Boundary conditions and external loads are allowed in the state law, thus extending previous works where the stress-free hypothesis turns out to be essential. A rigorous mathematical analysis is then carried out to prove the well-posedness of the problem. The numerical approximation is performed using gradient-based optimisation algorithms. Our main goal in this part is to show the possibility to apply inverse techniques for the numerical approximation of this problem, which allows us to address more generic situations than those covered by analytical approaches. Several numerical experiments for beam-like and shell-type geometries illustrate the performance of the proposed numerical scheme. [ABSTRACT FROM AUTHOR]

Background: One of the biggest challenges in soft robotics is the variability and controllability of stiffness. Jamming-based approaches have been of interest to change stiffness dramatically by increasing friction between grains, layers, or fibers. Besides, magnetorheological elastomers (MREs) that exhibit magnetic field-dependent viscoelasticity have significant potential as a stiffness variation material. This study investigates the unique mechanics of magnetic jamming of MRE sheets exploring stiffness change both due to jamming and variable viscosity. Methods: Sample MREs and flexible neodymium-iron-boron (NdFeB) magnets are manufactured. Uniaxial tensile tests supported with digital image correlation are performed to characterize the materials. Multi-layer jamming structures comprised of MREs and NdFeB magnets are developed and validated through 3-point bending experiments and finite element simulations. Results: Results show that the stiffness of the multi-layer structure is higher under magnetic field. Furthermore, the stiffness change is increased when MREs are used instead of PDMS as layers. Conclusion: This study proves the concept of magnetic jamming of MRE layers. The results are crucial for the possible soft robotic implementation of the proposed hybrid stiffening approach combining jamming with viscoelasticity modification. [ABSTRACT FROM AUTHOR]

As key structures in medical technology, soft robotics, and flexible electronics, the mechanical behavior of island-bridge structures has drawn great attention among the scientific community. However, the bending instability properties of island-bridge structures are still unclear, which hinders their function realization and design. Herein, the bending behavior of the island-bridge structure is comprehensively explored by experiment, numerical simulation, and theoretical analysis. It is found that the island-bridge structures can produce upward or downward morphologies under the bending loads, which is attributed to the coupling effect of combined loadings on the upper films. The bending morphology and the critical load can be well tuned by changing the corresponding material and geometric parameters or introducing creases in the upper film. The results should be of significant importance for the development of flexible electronics, soft robots, and biomedical engineering and enrich our knowledge of the mechanical properties of the island-bridge structure. [ABSTRACT FROM AUTHOR]

In minimally invasive surgery, such as cardiac ablation, magnetically steered catheters made of variable‐stiffness materials can enable higher dexterity and higher force application to human tissue. However, the long transition time between soft and rigid states leads to a significant increase in procedure duration. Here, a fast‐response, multisegmented catheter is described for minimally invasive surgery made of variable‐stiffness thread (FRVST) that encapsulates a helical cooling channel. The rapid stiffness change in the FRVST, composed of a nontoxic shape memory polymer, is achieved by an active cooling system that pumps water through the helical channel. The FRVST displays a 66 times stiffness change and a 26 times transition enhancement compare with the noncooled version. The catheter allows for selective bending of each segment up to 127° in air and up to 76° in water under an 80 mT external magnetic field. The inner working channel can be used for cooling an ablation tip during a procedure and for information exchange via the deployment of wires or surgical tools. [ABSTRACT FROM AUTHOR]

Stimuli-responsive soft robots offer new capabilities for the fields of medical and rehabilitation robotics, artificial intelligence, and soft electronics. Precisely programming the shape morphing and decoupling the multiresponsiveness of such robots is crucial to enable them with ample degrees of freedom and multifunctionality, while ensuring high fabrication accuracy. However, current designs featuring coupled multiresponsiveness or intricate assembly processes face limitations in executing complex transformations and suffer from a lack of precision. Therefore, we propose a one-stepped strategy to program multistep shape-morphing soft millirobots (MSSMs) in response to decoupled environmental stimuli. Our approach involves employing a multilayered elastomer and laser scanning technology to selectively process the structure of MSSMs, achieving a minimum machining precision of 30 ^m. The resulting MSSMs are capable of imitating the shape morphing of plants and hand gestures and resemble kirigami, pop-up, and bistable structures. The decoupled multistimuli responsiveness of the MSSMs allows them to conduct shape morphing during locomotion, perform logic circuit control, and remotely repair circuits in response to humidity, temperature, and magnetic field. This strategy presents a paradigm for the effective design and fabrication of untethered soft miniature robots with physical intelligence, advancing the decoupled multiresponsive materials through modular tailoring of robotic body structures and properties to suit specific applications. [ABSTRACT FROM AUTHOR]

Bilayer hydrogel actuators, consisting of an actuating layer and a functional layer, show broad applications in areas such as soft robotics, artificial muscles, drug delivery and tissue engineering due to their inherent flexibility and responses to stimuli. However, to achieve the compatibility of good stimulus responses and high mechanical properties of bilayer hydrogel actuators is still a challenge. Herein, based on the double-network strategy and using the synchronous ultraviolet (UV) polymerization method, an upper critical solution temperature (UCST)-type bilayer hydrogel actuator was prepared, which consisted of a poly(acrylamide-co-acrylic acid)[MC] actuating layer and an agar/poly(N-hydroxyethyl acrylamide-co-methacrylic acid)[AHA] functional layer. The results showed that the tensile stress/strain of the bilayer hydrogel actuator was 1161.21 KPa/222.07%. In addition, the UCST of bilayer hydrogels was ~35 °C, allowing the bilayer hydrogel actuator to be curled into an "◎" shape, which could be unfolded when the temperature was 65 °C, but not at a temperature of 5 °C. Furthermore, hydrogel actuators of three different shapes were designed, namely "butterfly", "cross" and "circle", all of which demonstrated good actuating performances, showing the programmable potential of bilayer hydrogels. Overall, the bilayer hydrogels prepared using double-network and synchronous UV polymerization strategies realized the combination of high mechanical properties with an efficient temperature actuation, which provides a new method for the development of bilayer hydrogel actuators. [ABSTRACT FROM AUTHOR]

This study investigates the characteristics of a novel origami-based, elastomeric actuator and a soft gripper, which are controlled by hand gestures that are recognized through machine learning algorithms. The lightweight paper–elastomer structure employed in this research exhibits distinct actuation features in four key areas: (1) It requires approximately 20% less pressure for the same bending amplitude compared to pneumatic network actuators (Pneu-Net) of equivalent weight, and even less pressure compared to other actuators with non-linear bending behavior; (2) The control of the device is examined by validating the relationship between pressure and the bending angle, as well as the interaction force and pressure at a fixed bending angle; (3) A soft robotic gripper comprising three actuators is designed. Enveloping and pinch grasping experiments are conducted on various shapes, which demonstrate the gripper's potential in handling a wide range of objects for numerous applications; and (4) A gesture recognition algorithm is developed to control the gripper using electromyogram (EMG) signals from the user's muscles. [ABSTRACT FROM AUTHOR]

Origami is a rich source of inspiration for creating soft actuators with complex deformations. However, implementing the re‐foldability of origami on soft actuators remains a significant challenge. Herein, a universal and programmable re‐foldability strategy is reported to integrate multiple origami patterns into a single soft origami actuator, thereby enabling multimode morphing capability. This strategy can selectively activate and deactivate origami creases through variable stiffness fibers. The utilization of these fibers enables the programmability of crease pattern quantity and types within a single actuator, which expands the morphing modes and deformation ranges without increasing their physical size and chamber number. The universality of this approach is demonstrated by developing a series of re‐foldable soft origami actuators. Moreover, these soft origami actuators are utilized to construct a bidirectional crawling robot and a multimode soft gripper capable of adapting to object size, grasping orientation, and placing orientation. This work represents a significant step forward in the design of multifunctional soft actuators and holds great potential for the advancement of agile and versatile soft robots. [ABSTRACT FROM AUTHOR]

[Display omitted] • By incorporating MXene nanosheets and Fe3+ into the hydrogel network, rapid gelation (within 10 s) was achieved. • This dual-network conductive hydrogel composite exhibited outstanding stretchability, extremely low energy dissipation. • This work provides a feasible platform for developing integrated wearable health-monitoring electronic systems. Hydrogel-based functional materials had attracted great attention in the fields of artificial intelligence, soft robotics, and motion monitoring. However, the gelation of hydrogels induced by free radical polymerization typically required heating, light exposure, and other conditions, limiting their practical applications and development in real-life scenarios. In this study, a simple and direct method was proposed to achieve rapid gelation at room temperature by incorporating reductive MXene sheets in conjunction with metal ions into the chitosan network and inducing the formation of a polyacrylamide network in an extremely short time (10 s). This resulted in a dual-network MXene-crosslinked conductive hydrogel composite that exhibited exceptional stretchability (1350 %), remarkably low dissipated energy (0.40 kJ m−3 at 100 % strain), high sensitivity (GF = 2.86 at 300–500 % strain), and strong adhesion to various substrate surfaces. The study demonstrated potential applications in the reliable detection of various motions, including repetitive fine movements and large-scale human body motions. This work provided a feasible platform for developing integrated wearable health-monitoring electronic systems. [ABSTRACT FROM AUTHOR]