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Research on small‐scale soft robots has emerged in recent years, and various soft actuators have been developed to implement various actions. Nevertheless, realizing self‐sensing alongside environmental sensing capabilities remains a challenge, largely due to the constraints imposed by compact dimensions and the limited load‐bearing capacity intrinsic to these robots. In this study, an innovative approach is introduced through the development of a visualized sensing integrated soft actuator, which harnesses the actuator's color as a straightforward and real‐time sensing medium. Additionally, a multi‐responsive actuation mechanism is adopted in which the actuator responds concurrently to both electric and magnetic fields. To exemplify the efficacy of this concept, the actuators are engineered as flexible soft grippers, thereby accommodating functions encompassing grasping and transporting. Relying on the color distribution manifested by the actuator, the actuator's self‐sensing ability alongside its capacity to discern object temperatures is demonstrated. Such a soft actuator provides new perspectives in the realm of soft robotics, showing great potential in diverse robotic applications. [ABSTRACT FROM AUTHOR]

In article number 1806698, Guoying Gu, Qi Ge, and co‐workers develop a paradigm to design and manufacture fast‐response, stiffness‐tunable (FRST) soft actuators via hybrid multimaterial 3D printing. The robotic gripper with three FRST actuators demonstrates a high load capacity and shape adaptivity by lifting objects with arbitrary shapes and various weights spanning from less than 10 g to 1.5 kg. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) demonstrates clear advantages over other imaging modalities in neurosurgery with its ability to delineate critical neurovascular structures and cancerous tissue in high‐resolution 3D anatomical roadmaps. However, its application has been limited to interventions performed based on static pre/post‐operative imaging, where errors accrue from stereotactic frame setup, image registration, and brain shift. To leverage the powerful intra‐operative functions of MRI, e.g., instrument tracking, monitoring of physiological changes and tissue temperature in MRI‐guided bilateral stereotactic neurosurgery, a multi‐stage robotic positioner is proposed. The system positions cannula/needle instruments using a lightweight (203 g) and compact (Ø97 × 81 mm) skull‐mounted structure that fits within most standard imaging head coils. With optimized design in soft robotics, the system operates in two stages: i) manual coarse adjustment performed interactively by the surgeon (workspace of ±30°), ii) automatic fine adjustment with precise (<0.2° orientation error), responsive (1.4 Hz bandwidth), and high‐resolution (0.058°) soft robotic positioning. Orientation locking provides sufficient transmission stiffness (4.07 N/mm) for instrument advancement. The system's clinical workflow and accuracy is validated with lab‐based (<0.8 mm) and MRI‐based testing on skull phantoms (<1.7 mm) and a cadaver subject (<2.2 mm). Custom‐made wireless omni‐directional tracking markers facilitated robot registration under MRI. [ABSTRACT FROM AUTHOR]

The ocean environment has enormous uncertainty due to the influence of complex waves and undercurrents. The human beings are limited in their abilities to detect and utilize marine resources without powerful tools. Soft robots employ soft materials to simplify the complex mechanical structures in rigid robots and adapt their morphology to the environment, making them suitable for performing some challenging tasks in place of manual labor. Due to superior flexible and deformable bodies, underwater soft robots have played significant roles in numerous applications in recent decades. Meanwhile, various technical challenges still need to be tackled to ensure the reliability and practical performance of underwater soft robots in complicated ocean environment. Nowadays, some researchers have developed underwater soft robotic systems based on biomimetics and other disciplines, aiming at comprehensive exploration of ocean and appropriate utilization of unexploited resources. This review presents the recent advances of underwater soft robots in the aspects of intelligent soft materials, fabrication, actuation, locomotion patterns, power storage, sensing, control, and modeling; additionally, the existing challenges and perspectives are analyzed as well. [ABSTRACT FROM AUTHOR]

Soft robotics enriches the robotic functionalities by engineering soft materials and electronics toward enhanced compliance, adaptivity, and friendly human machine. This decade has witnessed extraordinary progresses and benefits in scaling down soft robotics to small scale for a wide range of potential and promising applications, including medical and surgical soft robots, wearable and rehabilitation robots, and unconstructed environments exploration. This perspective highlights recent research efforts in miniature soft robotics in a brief and comprehensive way in terms of actuation, powering, designs, fabrication, control, and applications in four sections. Section 2 discusses the key aspects of materials selection and structural designs for small‐scale tethered and untethered actuation and powering, including fluidic actuation, stimuli‐responsive actuation, and soft living biohybrid materials, as well as structural forms from 1D to 3D. Section 3 discusses the advanced manufacturing techniques at small scales for fabricating miniature soft robots, including lithography, mechanical self‐assembly, additive manufacturing, tissue engineering, and other fabrication methods. Section 4 discusses the control systems used in miniature robots, including off‐board/onboard controls and artificial intelligence‐based controls. Section 5 discusses their potential broad applications in healthcare, small‐scale objects manipulating and processing, and environmental monitoring. Finally, outlooks on the challenges and opportunities are discussed. [ABSTRACT FROM AUTHOR]

Soft pneumatic biomimetic robotic systems excel at the specific application they are designed for, often to interact or navigate unstructured environments safely. However, redeployment to new purposes requires substantial resources, from redesign to revalidation. Despite most pneumatic artificial muscles surpassing the power and contraction performance of natural muscles, natural muscles largely remain unmatched in terms of their versatility and complex performance. This is likely due to artificial muscle's low effective strain and high radial expansion, limiting parallel operating efficiencies. To address these challenges, a class of compact versatile pneumatic actuators, called multilayer artificial muscle (MAM), that are capable of deployment to different applications through configurable modularity, is presented. The MAMs are biomimetically inspired by the sarcomere, the building block for natural muscle architecture. Similarly, MAM can extend and contract as well as be rearranged to mimic muscle‐like actions and functions, such as a caterpillar locomotion robot and an entire robotic arm. The MAMs are fabricated through multilayer, multimaterial, low‐cost additive manufacturing, which offers certain advantages such as higher extension, contraction force, and durability. MAMs have the potential to provide a crucial fundamental building block toward future versatile reconfigurable architecture. [ABSTRACT FROM AUTHOR]

Soft robotics systems are currently under development using ionic electroactive polymers (i‐EAP) as soft actuators for the human‐machine interface. However, this endeavor has been impeded by the dilemma of reconciling the competing demands of force and strain in i‐EAP actuators. Here, the authors present a novel design called "ions‐silica percolated ionic dielectric elastomer (i‐SPIDER)", which exhibits ionic liquid‐confined silica microstructures that effectively resolve the chronic issue of conventional i‐EAP actuators. The i‐SPIDER actuator demonstrates remarkable electromechanical conversion capacity at low voltage, thanks to improved ion accumulation facilitated by interpreting electrode polarization at the electrolyte‐electrode interface. This approach concurrently enhances both strain (by approximately 1.52%) and force (by roughly 1.06 mN) even at low Young's modulus (merely 5.9 MPa). Additionally, by demonstrating arachnid‐inspired soft robots endowed with user‐desired tasks through control of various form factors, the development of soft robots using the i‐SPIDER that can concomitantly enhance strain and force holds promise as a compelling avenue for ushering in the next generation of miniaturized, low‐powered soft robotics. [ABSTRACT FROM AUTHOR]

Soft robotic actuators can be designed to achieve complex and tailored motions while simultaneously leveraging their compliance to interact with complex and often delicate environments. Mechanical metamaterials reveal a route to customizable deformations, force exertion, and mechanical energy efficiency attainable by careful arrangement of local geometric features. Herein, modular soft robotic actuators are developed from soft elastomers and flexible thermoplastic sheets of various unit cell designs. The efforts are focused on center‐symmetric perforated sheets, which are formed into flexible cylindrical skins that surround the soft inflatable actuators. The results demonstrate the influence of perforation geometry on the spatial stiffness of the reinforcement structure and the proposed actuators' response through several investigations. It is demonstrated that the free‐boundary displacement, maximal force exertion, and mechanical energy efficiency of extensile actuators are dependent on a change of deformation mode in the mesostructure. The spatial stiffness concept is extended to develop soft robotic actuators that can bend, twist, and perform hybrid motions, such as simultaneous bending and twisting. Multisegment soft robotic arms are also developed from the aforementioned actuators. Investigations in this study provide a step toward the development of highly customizable and programmable soft robotic actuators for various applications. [ABSTRACT FROM AUTHOR]

Soft robots are able to safely operate in a dynamically evolving or highly unstructured environment by virtue of their inherited compliance. Among the available actuation methods for soft robotics, fluid‐driven is frequently preferred due to holistic design considerations that enable multipurpose yet straightforward mechanical solutions to complicated issues. The motion of a soft fluid‐driven robotic system usually relies on the flow of its internal fluid, however, existing fluid pumps only enable a single linear flow, which severely hinders the integrated multifunctional design of soft robots. Herein, a class of liquid manipulator is proposed based on electrohydrodynamic (EHD) effect, which consists of a flexible substrate with a printed planar electrode pattern. By streamlining the electric field distribution via electrode pattern, the liquid manipulator can manipulate the fluid flow, allowing fluid to perform multiple movement behaviors, including tangential, radial, and linear motions. These liquid manipulators are fabricated by printing planar electrode patterns onto flexible substrates using the digital printing method, in which both the printed electrodes and substrate are flexible and bendable. These liquid manipulators are flexible, fast‐response, thin, lightweight, and scalable, which can be easily embedded into soft fluidic systems with insignificant footprint and weight and actuate their rapid movements. Three liquid manipulators are embedded into a continuously rotating motor, focus‐tunable liquid lens, and soft linear actuator to achieve their multiple motions, i.e., continuous rotation, radial motion, and linear motion, illustrating broad potential of liquid manipulators in soft robotic systems. [ABSTRACT FROM AUTHOR]

Conventional robotic systems are built with rigid materials to deal with large forces and predetermined processes. Soft robotics, however, is an emerging field seeking to develop adaptable robots that can perform tasks in unpredictable environments and biocompatible devices that close the gap between humans and machines. Dielectric elastomers (DEs) have emerged as a soft actuation technology that imitates the properties and performance of natural muscles, making them an attractive material choice for soft robotics. However, conventional DE materials suffer from electromechanical instability (EMI), which reduces their performance and limits their applications in soft robotics. This review discusses key innovations in DE artificial muscles from a material standpoint, followed by a survey on their representative demonstrations of soft robotics. Specifically, we introduce modifications of DE materials that enable large strains, fast responses, and high energy densities by suppressing EMI. Additionally, we examine materials that allow variable stiffness and self‐healing abilities in DE actuators. Finally, we review dielectric elastomer actuator (DEA) applications in soft robotics in four categories, including automation, manipulation, locomotion, and human interaction. [ABSTRACT FROM AUTHOR]

Soft robots adapt passively to complex environments due to their inherent compliance, allowing them to interact safely with fragile or irregular objects and traverse uneven terrain. The vast tunability and ubiquity of textiles has enabled new soft robotic capabilities, especially in the field of wearable robots, but existing textile processing techniques (e.g., cut‐and‐sew, thermal bonding) are limited in terms of rapid, additive, accessible, and waste‐free manufacturing. While 3D knitting has the potential to address these limitations, an incomplete understanding of the impact of structure and material on knit‐scale mechanical properties and macro‐scale device performance has precluded the widespread adoption of knitted robots. In this work, the roles of knit structure and yarn material properties on textile mechanics spanning three regimes–unfolding, geometric rearrangement, and yarn stretching–are elucidated and shown to be tailorable across unique knit architectures and yarn materials. Based on this understanding, 3D knit soft actuators for extension, contraction, and bending are constructed. Combining these actuation primitives enables the monolithic fabrication of entire soft grippers and robots in a single‐step additive manufacturing procedure suitable for a variety of applications. This approach represents a first step in seamlessly "printing" conformal, low‐cost, customizable textile‐based soft robots on‐demand. [ABSTRACT FROM AUTHOR]

Unlike traditional hard grippers, soft robotic grippers are commonly made of soft materials so that the soft grippers can produce motion via elastic deformations of their compliant components. The advantages of compliance allow soft grippers to effectively eliminate shocks caused by hard contact, which usually occurs when a hard robotic gripper manipulates a hard object. Until now, the soft robotic grippers are able to operate numerous objects with irregular geometries and different textures. Besides, with the help of embedded sensors, soft robotic grippers have facilitated the growing automation of many tasks, which are thought to be far too delicate for robotic manipulation. This paper reviews the advancement in soft robotic grippers. The paper first introduces the actuation technologies followed by the design and fabrication techniques. The use of 3D printing techniques in the fabrication of the soft gripper is also discussed. The Review then highlights the challenges and future outlook in the fabrication of soft grippers and sensors. [ABSTRACT FROM AUTHOR]

Polymers with large and reversible light‐induced deformation offer a plethora of opportunities for the wireless control of small‐scale soft robots. However, their widespread adoption in real‐world applications is hindered, mainly due to their intrinsic softening upon illumination. Such limitation has detrimental effects on the achievable stress, durability, and precise positional control of the soft actuators after multiple cycles of use. Here, a synthetic rubber from a polybutadiene‐polyethylene copolymer is reported as a durable material for light‐controlled soft robots. The rubber can be programmed to exhibit various deformation modes controlled by visible‐to‐infrared light through a photothermal effect. Semi‐crystallinity of polyethylene within the rubbery network provides this material with a remarkable modulus at high temperatures (2.5 MPa at 100–140 °C), deformation repeatability (>90%) and shape‐recovery (>98%) after 100 actuation cycles subject to loads ranging from 10 to 10 000 times of its body weight (1.4 kPa–1.4 MPa). Soft robotic applications are demonstrated, such as thermally‐driven jumping and photo‐driven cargo transport carrying up to 1200 times its own weight. The results expand the portfolio of materials in designing remotely‐controlled, robust, and resilient soft robots working at small scales. [ABSTRACT FROM AUTHOR]

With advances in electronics, the concept of flexible electronics has left traditional designs behind. Many concepts, such as sensors, transistors, soft robotics, data, and energy storage devices have begun to find more widespread and flexible areas of use. From this point of view, using environmentally friendly, abundant, and renewable natural materials that reduce carbon emissions in the production and disposal of these components is the first step toward the concept of sustainable flexible electronics. This review deals with the integration of sustainable natural materials obtained from plant, animal, and bacterial sources into sensors, displays, data storage, power generation, and soft robotic systems, with appropriate examples compiled from the last ten years. In addition, limitations in the use of sustainable materials as flexible electronic components and their potential for use in innovative electronic applications in the future are foreseen. [ABSTRACT FROM AUTHOR]

The ultimate goal of the advancements in bioelectronics and robotics is the creation of seamless interfaces between artificial devices and biological structures. Current efforts in this area have been focused on designing biocompatible, mechanically compliant, and minimally invasive electronic and robotic systems for a range of applications, such as motor control and sweat sensing. The purposeful design of bioelectronic and robotic systems using the principles of biomimicry enables the creation of biocompatible and life‐like machines and electronics. The success of such approaches relies on the new development and applications of soft materials, as well as methods of actuation and sensing that are inspired, either by composition, function, or properties, of the naturally occurring organisms. A combination of rigid structural components, soft actuators, and flexible sensors can enable the integration of such devices with biological organisms and eventually human users. In this review, we highlight the recent advances in biomimetic soft robotics and bioelectronics. We describe the soft robotic fabrication toolbox and modern solution in bioelectronics that, in our opinion, will enable the fusion of these fields by creating robotic bioelectronic systems. Future development in this area will require substantial integration of adaptable and responsive components at the biointerfaces. [ABSTRACT FROM AUTHOR]

Research field of soft robotics develops exponentially since it opens up many imaginations, such as human‐interactive robot, wearable robots, and transformable robots in unpredictable environments. Wet environments such as sea and in vivo represent dynamic and unstructured environments that adaptive soft robots can reach their potentials. Recent progresses in soft hybridized robotics performing tasks underwater herald a diversity of interactive soft robotics in wet environments. Here, the development of soft robots in wet environments is reviewed. The authors recapitulate biomimetic inspirations, recent advances in soft matter materials, representative fabrication techniques, system integration, and exemplary functions for underwater soft robots. The authors consider the key challenges the field faces in engineering material, software, and hardware that can bring highly intelligent soft robots into real world. [ABSTRACT FROM AUTHOR]

Abstract: This description of “soft robotics” is not intended to be a conventional review, in the sense of a comprehensive technical summary of a developing field. Rather, its objective is to describe soft robotics as a new field—one that offers opportunities to chemists and materials scientists who like to make “things” and to work with macroscopic objects that move and exert force. It will give one (personal) view of what soft actuators and robots are, and how this class of soft devices fits into the more highly developed field of conventional “hard” robotics. It will also suggest how and why soft robotics is more than simply a minor technical “tweak” on hard robotics and propose a unique role for chemistry, and materials science, in this field. Soft robotics is, at its core, intellectually and technologically different from hard robotics, both because it has different objectives and uses and because it relies on the properties of materials to assume many of the roles played by sensors, actuators, and controllers in hard robotics. [ABSTRACT FROM AUTHOR]

Traditional robots are machines programmed to accomplish tasks, thanks to a complex ensemble of sensors connected to a computer "brain" which elaborate signals to drive specific actions. This complex network suffers from limitations—the need for a central computer, for instance, poses a limit to device miniaturization and requires a large amount of energy. A promising development, made possible by recent advances in material science, endeavors a new generation of soft robots that are multifunctional, compliant, and autonomous in ways that are similar to biological organisms. In particular, photoresponsive polymers are demonstrated to be valid candidates to substitute the computer‐based intelligence with an "intrinsic" material cleverness. First demonstrations of self‐sustained motions as oscillations or autonomous walking are described. In these cases, light also provides a solution to a second, very important, issue in microrobotics, which is the availability of a source of energy. Light actuation together with smart polymers can be combined into self‐controlled robots capable of simple decision‐making processes, for example with robotic grippers that are able to distinguish particles with different colors. In addition, the most recent examples about the integration of a form of robotic "intelligence" into a single material with a minimal level of consciousness are reported. Self‐regulating behavior of smart materials reveals an intriguing possibility to integrate robot intelligence, especially at the microscale that is inaccessible by miniaturizing robot multifunctionality. This review highlights developments and applications of responsive materials able to recognize a certain stimulus and convert it into a specific autonomous action as "deciding" to grab or not to grab micro objects depending on their optical properties. [ABSTRACT FROM AUTHOR]

Soft robotic technologies have been known to have various advantages over their rigid counterparts due to their compliant and deformable properties. They can carry out delicate object manipulation and perform complex maneuvers in confined spaces, which traditional robotics has difficulty with. The most widely adopted fabrication method for traditional soft elastomeric fluidic actuators is mold‐casting, which is cumbersome and involves several manual steps. Therefore, a substantial variability in performance and quality of these actuators arises directly from the manufacturing process. This paper presents on a novel fold‐based design of a 3D‐printed soft pneumatic bending actuator. In contrast to other works that rely on high‐end multimaterial 3D printers, a consumer‐grade open source 3D printer to fabricate soft pneumatic actuators in a fast and cheap way using fused deposition modeling technology has been adapted. This allows for consistency in both the quality of the actuators and their mechanical performance. The key findings in (1) a 3D‐printed fold‐based actuator fabrication process, (2) actuator characterization, and (3) a design‐centric approach toward different bending profiles for different applications are presented. Manufacturing of soft pneumatic actuators could not have been easier with 3D printing of flexible materials. A novel fold‐based design‐based approach through 3D printing enhances the performance of soft pneumatic actuators while conferring abilities to bend into different configurations. This design can also be fundamentally used to manufacture soft pneumatic actuators found in a variety of functional applications. [ABSTRACT FROM AUTHOR]