Soft robotics最新文献

The tip-growing robot, constructed from flexible film or nylon and powered by fluid pressure, has exhibited superior motion performance and high adaptability in complex and restricted environments for detection and manipulation. However, the insufficient stiffness caused by its flexibility limits its ability to carry heavy loads in long and complex three-dimensional spaces. To address this, the study proposed a novel layer jamming mechanism inspired by the subcutaneous scales of freshwater eels. The discrete and continuous flaps, integrated and jammed between the designed double-layered body, increase the global stiffness without impairing tip eversion and steering capabilities. The internal pressure driving the eversion replaces the conventional vacuum system to provide the compression force, reducing lag and complexity. Additionally, the tip interspace between the two body layers ensures steering flexibility of the hardening robot and realizes shape locking post-deformation. The test shows that this mechanism increases the bending stiffness, torsional stiffness, and joint stiffness of the robot by 4.6, 7.8, and 8.7 times, respectively. Further, we demonstrate and verify the long-distance movement and superior carrying abilities in three-dimensional spaces, confirming that the tip-growing soft robot with jamming layers has broader application potential.

This article presents a bioinspired pneumatic soft actuator designed to achieve asymmetrical spatiotemporal deformations, inspired by the dynamic motion of human walking. The actuator's key innovation is a half-crossing structure that enables controlled airflow to produce complex bending and linear motions using only two air tubes. This design significantly reduces structural complexity and energy consumption compared with conventional soft actuators, which often require multiple air channels to achieve similar deformations. The actuator mimics the stance and swing phases of locomotion, allowing precise multidirectional movements, including forward, backward, and turning motions. A passive feedforward control strategy further enhances movement flexibility without the need for complex feedback systems. Experimental results demonstrate the actuator's adaptability and efficiency when integrated into a hexapod robot, with optimized performance through adjustments in air pressure and cycle duration. This work offers a versatile and energy-efficient solution for adaptive locomotion in soft robotics, advancing the field through a novel approach to actuator design.

It is challenging to simultaneously estimate the shape and contact force of miniature continuum surgical robots due to the limited sensing capabilities, deformable structure, and complexity of the external environment they operate in. In this work, the integration of a quaternion-based multicontact Cosserat model with contact force regularization enables a dual-pronged approach for simultaneous shape and body contact force estimation using minimum shape measurement input (i.e., tip position). In addition to internal actuation, cable friction, and material nonlinearity, the proposed state estimation approach also accounts for multiple environmental contacts with clinically relevant mixed geometric constraints (point, plane, and curved surface), as these complex and variable anatomical interactions critically influence the robot's behavior. The solving procedure is then reformulated as a nonlinear large-scale optimization problem to improve the state estimation robustness. Finally, both simulations and experiments on a cable-driven variable-stiffness notched-tube continuum robot were conducted to validate the proposed state estimation approach, demonstrating a comparable level of accuracy to state-of-the-art methods.

Pneumatic soft actuators hold great potential in applications such as surgery and artificial muscles, while facing limitations mainly due to external pumps. This study presents an origami-inspired soft actuator eliminating traditional pumps through a liquid-gas phase transition mechanism. This actuator undergoes axial stretching below a critical pressure of 5.5 kPa and radial expansion above this pressure, demonstrating bimodal deformation. This dual-mode response enables high output force and versatile deformation, suitable for applications like channel dilation and occlusion. By integrating origami's geometric programmability with soft materials, deformation is easily controlled via simple processing, yielding a bioinspired gripper. Additionally, actuators integrating magnetic terminals achieve inchworm-like multigait motion in confined spaces, highlighting broad potential applications. Our constructed origami-inspired wireless pneumatic soft actuator enables overcoming previous functionality and deformation mode limitations, providing compact programmable solutions that advance soft robotics.

Soft robots hold great promise but are notoriously difficult to control due to their compliance and back-drivability. In order to implement useful controllers, improved methods of perceiving robot pose (position and orientation of the entire robot body) in free and perturbed states are needed. In this work, we present a holistic approach to robot pose perception in free bending and with external contact, using multiple soft strain sensors on the robot (not collocated with the point of contact). By comparing the deviation of these sensors from their value in an unperturbed pose, we are able to perceive the mode and magnitude of deformation and thereby estimate the resulting perturbed pose of the soft actuator. We develop a sample 2 degree-of-freedom soft finger with two sensors, and we characterize sensor response to front, lateral, and twist deformation to perceive the mode and magnitude of external perturbation. We develop a data-driven model of free-bending deformation, we impose our perturbation perception method, and we demonstrate the ability to perceive perturbed pose on a single-finger and a two-finger gripper. Our holistic contact identification method provides a generalizable approach to perturbed pose perception needed for the control of soft robots.

This study explores the design and performance of origami robotic grippers fabricated through hard-soft coupled multimaterial three-dimensional (3D) printing. We evaluate the impact of design parameters on the kinematic behavior and mechanical functionality of the gripper. A kinematic model is employed to characterize the reachable workspace and motion capabilities, revealing that variations in geometric parameters significantly influence the origami gripper's performance. Furthermore, we explore the mechanical properties of the gripper by manipulating parameters such as soft hinge thickness and crease design, establishing a comprehensive relationship between geometric design and mechanical response. Experimental evaluations demonstrate the interplay between bending angle, force-displacement characteristics, and stiffness in the origami grippers. This research contributes to the optimization of origami-inspired robotic structures, highlighting the potential of multimaterial 3D printing techniques in developing flexible, adaptive, and efficient robotic applications.

Octopuses can effectively interact with environments using their agile suction cups, in which abundant neuroreceptors are embodied inside. Inspired by this, we proposed an electronics-integrated self-guided adhesive suction cup (E-SGAS) capable of environmental sensing and adaptively adhesion on diverse surfaces. E-SGAS features an inflatable adhesive membrane and an under-actuated design, enabling it to adapt to various angles and surface roughness under low preloads. A theoretical model is presented to predict self-guided adhesion outcomes. The integrated multilayer stretchable liquid metal sensory circuit (with a maximum deformation rate of 186%) in the adhesive membrane allows for detecting expansion, contact, suction, leakage, and surface roughness. E-SGAS can also process the sensory information to guide intelligent gripping in various complex environments. Experimental results demonstrate the ability of E-SGAS to autonomously grip under a preload force of 0.11 N, a maximum adhesion force of 57.9N, and a detachment force of only 0.34 N. It can adhere to surfaces up to 60-grit roughness and accommodate a surface with a relative angle of 90°. We also show that E-SGAS can capture flying objects or work in a confined space. The proposed adhesion and sensing strategies aim to enhance the performance and expand the application range of suction cup-like grippers. E-SGAS's results can provide design insights into creating stretchable electronics-integrated bioinspired adhesive systems that can interact with unconstructed environments.

This article presents a unique soft robot comprised of highly compliant locomotive modules interconnected with jamming-capable flexible envelopes. The modules incorporate origami-inspired actuators and suction cups for robust omnidirectional locomotion, acting as collective elements that drive the system's movement and control. The flexible envelopes enable dynamic interactions with the environment through stiffness modulation via granular jamming. A unified pneumatic actuation system consolidates all robot functions, simplifying the mechanical architecture. The system's capabilities are demonstrated through shape formation, object grasping and transportation, obstacle navigation, and diverse terrain locomotion experiments, highlighting its adaptability and cooperative nature. Furthermore, a simulation-based design optimization approach using a genetic algorithm enhances the system's grasping performance by exploring the different module and envelope configurations. The interconnected soft robot system represents a unique fusion of highly compliant modules and bodies, advancing modular soft robotics for effective environmental interactions.

Recently, there has been an increased interest in endowing intelligent behaviors and features in soft robotic systems. As a prerequisite for intelligence, a system must integrate sensing, information processing, and the ability to act in response to external stimuli. This work presents a soft robotic crawler that demonstrates locomotion using electroactive liquid crystal elastomers (LCEs). By integrating independent components such as a photo-responsive LCE switch into a conductive electromechanical processing network based on sequential logic, the robot can sense optical indicators and process this information to change direction autonomously. This study expands the design of the individual mechanical material subsystems and experimentally showcases the autonomous operation of the soft robot. The embedded bistable mechanism stores the present operational state of the robot and enforces directional locomotion by controlling the position of a mechanical hard stop that interfaces with the legs. The robot exemplifies the advanced potential of soft intelligent material systems for complex autonomous behavior, leveraging the unique properties of LCEs and a mechanical-electrical network for information processing without the need for traditional electronic controllers.

Robotic links play a vital role in transmitting force and torque, ensuring precise robotic movements. Traditional rigid links, typically made from metals, pose a risk of injury in human-robot interactions or damage to other objects due to their noncompliant and stiff nature and have limited adaptability across various tasks. Variable stiffness robotic links (VSRLs) using hydraulically amplified self-healing electrostatic (HASEL) actuators offer a solution, enhancing safety and adaptability while maintaining precision. This study introduces an electrohydraulic jammed VSRL utilizing a strip-shaped HASEL actuator, which stiffens upon application of high-voltage, pressurizing dielectric liquid encased in a dielectric bladder to achieve stiffness variations up to 8.3 times. The VSRL, optimized by adjusting liquid volume and sealing patterns, is lightweight and compact and eliminates the need for bulky pumps and motors. It also functions as a capacitor, enabling a self-sensing strategy to detect deformation. Experimental results demonstrate significant stiffness variability and effective load-bearing capabilities. Multi-VSRL assemblies further enhance stiffness for practical applications, including collaborative robotic links and wearable robots for joint support. A unique drone application showcases the VSRL's potential for energy-efficient aerial operations. The proposed VSRL represents a promising advancement in robotic technology, offering improved safety, adaptability, and functionality for diverse real-world applications.