Soft robotics最新文献

Tensegrity-based continuum manipulators (TCMs) are rigid-flexible coupling mechanisms that show great promise for applications in unstructured environments by actively or passively conforming to objects. However, the coupling effects of TCMs require significant effort in resolving the actuation redundancy for performing dexterous manipulation tasks. Inspired by the functions of the elephant trunk, this article proposes a modular TCM composed of preprogrammable bend-twist modules (PBTMs) that employ enhanced segmented actuation. This actuation strategy effectively decouples adjacent segments and separates curvature and directional control, simplifying both mechanical integration and control implementation. By designing a preprogramming template attached to the end module, various twisting motions can be achieved in situ, achieving the multimodal deformation of the PBTM. In this setup, the manipulator is capable of bending or twisting in various planes, enabling the manipulator to better conform with objects of varying shape and pose. Then, we derived a dynamic model in terms of natural coordinates with clustered cable (CTC) elements to predict the configuration of the manipulator. Based on the numerical results, we analyze the effect of the CTCs' rest length on the cable slack phenomenon during the bending motion, as well as the in situ preprogrammed twist motion of the manipulator. Finally, we fabricated a manipulator prototype consisting of two PBTMs and showcased its versatile multimodal deformation in experimental scenarios for object wrapping and obstacle avoidance. The experimental results demonstrate that our proposed modular TCM provides a feasible paradigm, which reduces the control complexity of the continuum manipulator system.

Soft robotics solutions to unmet clinical needs represent an emergent disruptive technology. However, clear guidelines on the selection of sterilization methods that consider the preservation of essential physical and functional characteristics of such materials are presently lacking. We reviewed 76 studies that assessed the morphological, mechanical, and functional impact of sterilization on chemically stable and stimuli-responsive hydrogels and polymers. Gamma irradiation was well-tolerated in both stable and stimuli-responsive polymers and conferred additional beneficial material properties. Steam sterilization was suitable for most hydrogels and stimuli-responsive polymers, whereas ethylene oxide sterilization produced mixed effects in stable polymers.

Muscles, with broad contraction response bandwidth from milliseconds to seconds, are symmetrically distributed on both sides of the fish's body. By employing these symmetrical muscles with different contraction response combinations, fish are capable of multimodal locomotion including crawling, jumping, rolling, escaping, and swimming. These locomotion modes, ranging from water to land, enable fish with simple body structure to have strong survival abilities. This work proposes a teleost-inspired multimodal locomotion soft robot, named TMSR, which is capable of multimodal locomotion in both underwater and terrestrial environments. The TMSR features a fish-like simple structure with two shape memory alloy (SMA) artificial muscles, each with different contraction response bandwidths, asymmetrically arranged along its central plane. A series of contraction response combinations using these two SMA artificial muscles were developed for the multimodal locomotion of TMSR. Through performance experiments and mechanical models, the driving characteristics of the SMA artificial muscles and the key factors influencing their contraction responses were explored. The TMSR exhibits excellent adaptability and adjustability across various terrains, achieving five different modes of locomotion similar to the movement behaviors of fish through a lightweight and simple biomimetic structural design, including the unique escape movement, which is uncommon in current soft locomotion robots. This design endows the TMSR with a lower mass-mode ratio and higher flexibility and multifunctionality compared with similar robots. This research contributes to broadening the application prospects of such robots in diverse environments.

Cable-climbing robots are essential for performing inspection and maintenance in hard-to-reach places with a cable-based infrastructure. However, current robots are often either cumbersome, have low load capacities or struggle to accommodate cables with largely varying diameters. To address these issues with a single design, this study demonstrates an origami-based, cable-climbing soft robot capable of caterpillar-like anchor-crawling locomotion. This robot weighs around 110 g and consists of a body mechanism and two leg mechanisms. The body mechanism with sufficient compliance can adapt to various bends of the cables. The leg mechanism utilizes a bionic gripping design that enables it to climb cables with diameters ranging from less than 1 mm to tens of millimeters. Additionally, the bistable performance of the leg mechanism allows the robot to secure itself to cables within a certain diameter range, even without continuous actuation. Moreover, the robot has a good load capacity and, for instance, can carry a load of more than ten times its weight on a vertical cable with a diameter of 30 mm. More capabilities of the robot are also demonstrated, including crawling between cables with different diameters, traversing protruding obstacles, transporting items, and completing complex tasks, such as repairing damaged cables.

In this work, we introduce the Jamming Adjustable PneuNet Actuator (JAPA), a novel soft robotic finger that enables both stiffness modulation and tunable bending behavior through a flexible hybrid jamming approach. This method combines the high stiffness gain of layer jamming and the adaptability of granular jamming. By adjusting the effective length of the paper-based layer jamming using a magnetically positioned sliding mechanism, JAPA can dynamically reshape its bending profile. Meanwhile, the granular jamming element distributed throughout the finger can provide adaptive stiffness reinforcement across all bending configurations. The combination of adjustable stiffness and reconfigurable bending profile substantially enhances JAPA's multidirectional force control and dexterity. To evaluate its performance, we conducted a series of experiments to assess JAPA's stiffness modulation, pull-off and output forces, multidirectional force control, and workspace. Experimental results demonstrate that JAPA can achieve a maximum stiffness gain of up to 3.55×, with adjustable stiffness distribution contributing to a workspace expansion exceeding 200% and a more than 300% improvement in multidirectional force modulation. To visualize its multidirectional force control ability, we used a single JAPA unit to operate a computer cursor via a TrackPoint, dragging the cursor in different directions. To further validate its manipulation capability, we constructed a four-unit JAPA gripper capable of in-hand object rotation and safe handling of diverse objects, including delicate and irregularly shaped items. The proposed soft finger design holds promise for applications in assistive robotics, adaptive grasping, and human-interactive devices, where both safety and functional versatility are critical.

This article presents an origami actuator with a tunable limiting layer based on hybrid pneumatic and motor actuation. The main structure of the actuator is based on the Miura origami structure with a strain-limiting layer. Under air pressurization, the Miura origami actuator performs outward stretching deformation. A servomotor, which drives the limiting layer, can adjust its length on-demand. With combination of Miura origami actuator and a limiting layer with tunable length, reprogramming of the actuator is realized. The actuator outputs outward extension and inward bending with different limiting layer lengths and achieves an adjustable bending angle from 28.5° to 171.9°. To verify the capability of the proposed actuator in terms of manipulation and motion, a soft robotic gripper, a crawling robot, and an amphibious robot were built based on this actuator design. The experiments show that origami actuators with tunable limiting layer can reconfigure their morphology to better adapt to different environments in the application of soft robots.

Grasping objects across vastly different sizes and physical states-including both solids and liquids-with a single robotic gripper remain a fundamental challenge in soft robotics. We present the Everything-Grasping (EG) Gripper, a soft end-effector that synergistically integrates distributed surface suction with internal granular jamming, enabling cross-scale and cross-state manipulation without requiring airtight sealing at the contact interface with target objects. The EG Gripper can handle objects with surface areas ranging from submillimeter scale 0.2 mm² (glass bead) to over 62,000 mm² (A4-sized paper and woven bag), enabling manipulation of objects nearly 3500$\times$ smaller and 88$\times$ larger than its own contact area (approximated at 707 mm² for a 30 mm diameter base). We further introduce a tactile sensing framework that combines liquid detection and pressure-based suction feedback, enabling real-time differentiation between solid and liquid targets. Guided by the Tactile-Inferred Grasping Mode Selection algorithm, the gripper autonomously selects grasping modes based on distributed pressure and voltage signals. Experiments across diverse tasks-including underwater grasping, fragile object handling, and liquid capture-demonstrate robust and repeatable performance. To our knowledge, this is the first soft gripper to reliably grasp both solid and liquid objects across scales using a unified compliant architecture.

Soft creatures like Drosophila larvae can quickly ascend tubular surfaces via rolling, a capability not yet replicated by soft robots. Here, we present a single-piece soft robot capable of rolling along tubular structures by sequentially actuating its built-in axial muscles. We reveal that the sequential actuation generates distributed spinning torques along the robot's curved axis, enabling continuous non-coaxial rolling-distinct from current gravity-dependent rolling solutions. This non-coaxial rolling mechanism allows the robot to swiftly navigate tubular surfaces while conforming to their shapes and maintaining a stable grip. The robot's deformation and gripping force are actively adjusted to enhance its adaptability to various surfaces. We demonstrate that our robot can ascend pipes with varying geometries (e.g., varying-diameter, spiral-shaped, or non-cylindrical), traverse diverse terrains, pass through confined tunnels, and transition smoothly between planar rolling and pipe climbing. The robot's great adaptability and rapid movement underscore its potential for navigating scenarios with intricate surface geometries.

Soft robots offer adaptable, safe interactions in complex environments, with the potential for diverse applications, such as mimicking biological motions. One major challenge is designing and prototyping soft robots with varying deformation modes, which can be a time-consuming process. To address this hurdle, reconfigurable modular robots have emerged as a solution, allowing reusable and rapid prototyping into different soft robots. However, balancing simplicity in design with extensive deformation capabilities remains an open problem. Existing reconfigurable soft robotic modules have demonstrated adaptability, often relying on modular stacking to achieve a wide range of deformations. Typically, achieving complex deformations, such as forming a continuous curve, requires multiple modules connected in a chain, as each individual module can only transition between a limited set of predefined deformation states. We introduce SoftSnap modules: snap-together components that enable the rapid assembly of a class of untethered soft robots. Each SoftSnap module integrates computation, motor-driven string actuation, and a flexible thermoplastic polyurethane (TPU)-printed deformable structure, allowing a vast deformation range through different pre-wired string configurations. These modules connect seamlessly with other SoftSnap units or customizable connectors. Demonstrated configurations include starfish-like, brittle star, snake, 3D gripper, and ring-shaped robots, showcasing ease of assembly, adaptability, and functional diversity. The scalable, reconfigurable design of SoftSnap provides researchers with an efficient and flexible platform for rapidly prototyping untethered soft robotic systems.

Large-scale soft robots have the capability and potential to perform highly dynamic tasks such as hammering a nail into a board, throwing items long distances, or manipulating objects in cluttered environments. This is due to their joints being underdamped and their ability to store potential energy. The soft robots presented in this article are pneumatically actuated and thus have the ability to perform these tasks without the need for large motors or gear trains. However, getting soft robots to perform highly dynamic tasks requires controllers that can track highly dynamic trajectories to complete those tasks. For soft robots, this is a difficult problem to solve due to the uncertainty in their shape and their complicated dynamics and kinematics. This article presents a formulation of a model reference adaptive controller (MRAC) that causes a three-link soft robot arm to behave like a highly dynamic 2nd-order critically damped system. Using the dynamics of a 2nd-order system, we also present a method to generate joint trajectories for throwing a ball to a desired point in Cartesian space. We demonstrate the viability of our joint-level controller in simulation and on hardware with a reported maximum root mean square error of 0.0872 radians between a reference and executed trajectory. We also demonstrate that our combined MRAC controller and trajectory generator can, on average, throw a ball to within 25-28% of a desired landing location for a throwing distance of between 1.5 and 2 m on real hardware.