Continuum robots have been widely utilized in various fields, such as medical surgery, industrial manufacturing, and aerospace, due to their flexibility and compliance. However, their high structural compliance also presents significant challenges in achieving precise control. Although many existing continuum robots feature multiple degrees-of-freedom (DOFs) and complex control systems, such sophistication is often unnecessary for simple, repetitive, and task-specific applications where task-specific structures are more efficient. To address this issue, this paper proposes a parametric optimization-based automated design framework to generate structural models for multi-section 1-DOF flexure-joint-based continuum robots capable of achieving any two predefined end-effector poses. The proposed methodology employs a constant curvature assumption to simulate the bending characteristics of the continuum robot. MATLAB is used to optimize and solve the structural parameters, followed by the generation of 3D-printable models using the Solid Geometry Library Toolbox. Experimental results demonstrate that, under certain geometric boundary conditions for structural parameters, the robot’s end-effector can reach any two predefined poses with high accuracy. This approach significantly reduces the structural and control complexity of task-specific continuum robots, lowers manufacturing costs, and expands their range of applications.

Soft robotic systems enable safe and adaptive interaction in fields ranging from medicine to bioinspired in situ exploration. Most soft robots rely on elastomers for compliance, which limits controllability and strength. To address these limitations, a manufacturing strategy is presented that enables the fabrication of aluminum alloy‐based soft robots. Compliance in the metallic system is achieved through thin‐walled monolithic flexure structures. The manufacturing process utilizes vacuum investment casting and subsequent heat treatment to convert additively manufactured polymer or resin patterns into high‐strength Aluminum Alloy 7075 in T6 temper (AA7075‐T6) soft robotic components. Because the metallic structures behave linearly elastically, standard beam and flexure models can be used for design and kinematic prediction. Several functional components, including flexure joints, continuum manipulators, and grippers, are fabricated and tested. Experimental results confirm that wall thicknesses of 0.5 mm or less can be realized. The approach circumvents long‐standing limitations of elastomer‐based soft robotics and establishes a scalable path to high‐performance metal‐based soft robotic systems for demanding domains, including industrial automation and space applications.

Tendon-driven continuum robots (TDCRs) are increasingly used in complex environments for their flexibility. However, in rigid-segmented (disk-based) TDCRs, a tradeoff often arises between positional precision and compliance. In this article, we present a soft-rigid hybrid TDCR integrating silicone layers with 3D-printed units to balance performance. We develop a quasistatic kinematic/kinetostatic framework that incorporates tendon and joint friction. The model reproduces measured tip-deflection and curvature trends, and we report quantitative errors in tip position and tip angle across tested loads and actuation conditions, measured experimentally. We further benchmark the hybrid architecture against five alternatives of comparable geometry under standardized payload, hysteresis, and durability tests. Across these tests, the hybrid design offers the best overall tradeoff: smaller tip deflection under equal payload, lower hysteresis, and preserved bending amplitude with less drift over repeated cycles, yielding the highest composite score. As a proof of concept, the hybrid TDCR performed delicate manipulation; the central lumen supports through-lumen instrumentation (e.g., biopsy forceps). Clarifying modeling assumptions and providing quantitative validation, this study outlines a path to combining controllability with safe physical interaction in continuum manipulation, with potential applicability to human-robot interaction and medical engineering.

The application of tendon-driven continuum robots (TDCR) has rapidly expanded across various engineering fields due to their flexibility and dexterity. Discrete-jointed continuum robots are typically fabricated as segmented modules interconnected by joints, often resulting in extended prototyping timelines and elevated manufacturing costs. Besides, with identical compliant joints along the backbone, the real bending shape of the robot usually is an arc with variable curvature, resulting in uneven stress distribution along robot’s backbone. To cope with these problems, we propose a 3D-printed continuum robot incorporating convergent compliant joints, enabling monolithic fabrication and achieving balanced stress distribution along the backbone. Kinematic and kinetostatic analyses demonstrate the flexible manipulation, trajectory accuracy, and sufficient stiffness of the FDM-printed TDCR under varying tendon tensions and external forces. In addition, simulation and experimental results validate that the convergent compliant joint design improves stress distribution along the backbone.

Parallel robotic gripper is an efficient tool for grasping and manipulating objects in industrial applications. In recent years, to enable adaptive grasping of objects with complex shapes, many parallel grippers are equipped with soft robotic fingers. However, due to the low structural stiffness of the utilized soft materials, the grasping payload of the soft fingers is usually limited. To cope with this issue, we propose a topology-optimization-based method in this article to enhance the grasping payload of soft fingers for parallel grippers. Using a multiobjective algorithm, the adaptive grasping ability of the monolithic finger and the holding stiffness of the fingertip are taken into account in the optimization procedure. The realized finger is fabricated with thermoplastic polyurethane (TPU) material. To evaluate the soft-rigid hybrid performance of the synthesized finger, stiffness tests and grasping payload tests are also conducted. Experimental results show that the optimized finger has a higher payload capacity than the conventional finray-like soft finger, while maintaining similar adaptive grasping properties. Furthermore, a series of grasping tests have also demonstrated the grasping adaptability of the synthesized soft robotic finger for objects with different materials, shapes and weights.

In an aging society, the need for rehabilitation treatment is expected to rise. As current healthcare systems have limited capacity and personnel, access to rehabilitation devices usable in households can help address the demand. A lower-limb rehabilitation robot designed for home use must be adaptable to accommodate acute and chronic rehabilitation phases. Existing devices are mechanically complex and require intricate, patient-specific adjustments. To address this, we propose a single degree of freedom (DoF) mechanism based on a chain drive that can be used in multiple configurations, inside and outside a patient bed. We model the gait pattern and construct a custom cost function that captures key features of natural human walking. This cost function is then used to optimize the design parameters of the robot via a direct-search solver to accommodate patients of varying sizes and achieve effective rehabilitation with a fixed trajectory. The outcome is validated experimentally by comparing two robot configurations with five healthy subjects.

Amphibious robots require efficient locomotion strategies to enable smooth transitions between terrestrial and aquatic environments. Drawing inspiration from the undulatory movements of aquatic organisms such as cuttlefish and knifefish, this study introduces a bio-inspired propulsion system that emulates natural wave-based locomotion to improve adaptability and propulsion efficiency. A novel mechanism combining crank-rocker and sliding components is proposed to generate wave-like motions in robotic legs and fins, supporting both land crawling and aquatic paddling. By adopting a rigid-flexible coupling design, the system achieves a balance between structural integrity and motion flexibility. The effectiveness of the mechanism is systematically investigated through kinematic modeling, animation-based simulation, and experimental validation. The developed kinematic model captures the principles of wave propagation via the Crank-Slider-Rocker structure, offering insights into motion efficiency and thrust generation. Animation simulations are employed to visually validate the locomotion patterns and assess coordination across the mechanism. A functional prototype is fabricated and tested in both terrestrial and aquatic settings, demonstrating successful amphibious locomotion. The findings confirm the feasibility of the proposed design and underscore its potential in biomimetic robotics and amphibious exploration.

In recent years, soft continuum robots have emerged as a highly popular topic in robot manipulation. A typical application is in minimally invasive surgery, where their unique flexibility can be leveraged. Meanwhile, advancements in 3D printing technology have enabled the fabrication of complex geometries for continuum robots, which would be difficult to achieve using traditional manufacturing methods. However, some continuum robots, which contain large quantities of components, require extensive assembly processes. In addition, some 3D-printed continuum robots still face the challenge of confined degree of freedoms or low accuracy of motion. To address these challenges, we present a novel two-section tendon-driven continuum robot that can be fully fabricated through 3D printing in this research. The proposed continuum robot is composed of spring-based flexure joints and has six degrees of freedom. To evaluate the performance of the proposed structure, we have implemented an open-loop control method for trajectory following. Experimental results have also successfully demonstrated the motion accuracy of the proposed continuum robot structure.

Cutting‐edge applications require robots to be capable of navigating in different environments to improve the time and energy efficiency of travel and exploration. Amphibious robots address this need by operating in both aquatic and terrestrial settings, leveraging biomimetic designs and integrated mechanical propulsion systems. While these robots has traditionally drawn inspiration from reptiles, crustaceans, and amphibians, there has been comparatively less exploration of swimming‐capable mammals and birds as biological models. In this work, DuckyDog, a quadruped amphibious robot using erect posture has been proposed and developed to take full advantage of the high mobility of mammals on land. By integrating a duck‐like body and passive fins, it also has excellent swimming ability on the water surface. Whereas many robots rely on soft materials to construct compliant legs, DuckyDog is distinguished by its fused deposition modeling‐printed legs made from polylactic acid (PLA) filament, featuring structurally induced variable stiffness and actuated through a tendon‐driven mechanism. A series of experiments are conducted to evaluate DuckyDog's terrestrial and aquatic locomotion performance in both laboratory settings and complex natural environments, where it achieves maximum speeds of 0.40 body lengths per second on land and 0.30 in water.

Tendon-driven continuum robots (TDCR) are widely used in various engineering disciplines due to their exceptional flexibility and dexterity. However, their complex structure often leads to significant manufacturing costs and lengthy prototyping cycles. To cope with this problem, we propose a fused-deposition-modeling-printable (FDM-printable) TDCR structure design using a serial S-shaped backbone, which enables planar bending motion with minimized plastic deformation. A kinematic model for the proposed TDCR structure based on the pseudo-rigid-body model (PRBM) approach is developed. Experimental results have revealed that the proposed kinematic model can effectively predict the bending motion under certain tendon forces. In addition, analyses of mechanical hysteresis and factors influencing bending stiffness are conducted. Finally, A three-finger gripper is fabricated to demonstrate a possible application of the proposed TDCR structure.

In recent years, there has been a growing research focus on continuum robots due to their high flexibility and safety. Nevertheless, the inherent nonlinearity of the flexible structure of continuum robots has increased the complexity of their motion control. In this work, we propose a method based on model predictive control (MPC) to achieve the closed-loop motion control of a tendon-driven continuum robot. The robot has two bending degrees of freedom (DOFs) and the constant curvature model is used as the kinematic model. Selective laser sintering (SLS) technology is utilized to fabricate the entire continuum robot system, while a tracking camera is used to measure the robot position to provide the real-time feedback for the MPC controller. Experiments are also conducted, in which the continuum robot is actuated to move along different predefined plane trajectories. As a result, the position error of the MPC-based controller is much smaller than that of an open-loop controller, which demonstrates the good control performance of the proposed method.

The creation of realistic human phantoms is beneficial for medical training and surgical planning. Traditional methods for producing these phantoms are often complex, time-consuming, and costly, especially for models with specific anatomical variations. This paper introduces a novel method for the fabrication of patient-specific phantoms that utilizes large-scale material extrusion 3D printing technology. The Solid Geometry (SG) Library in MATLAB is used to convert surface models and medical imaging data into printable volume models. We detail the process of transforming these models, the printing techniques employed, and the post-processing methods used to improve the functionality of the final phantoms. The results demonstrate the capability of this method to produce large-scale phantoms potentially suitable for robotic surgery training, aiming to improve the preparedness and skills of medical practitioners.

Compared with the conventional rigid-link-based robots, walking robots with soft legs have the advantages of high environmental adaptability and safety, which can greatly enhance the performance of locomotion robots when exploring unknown regions. In order to further explore the design potential for soft walking robots, we propose in this paper a novel quadruped walking robot called Toqro, in which an improved design of topology optimized soft leg is introduced to achieve flexible walking motions. To simplify the kinematic analysis, the realized soft robotic leg is modeled as a two-linkage structure with two rotating degrees of freedom (DOFs). Each leg of the robot is actuated by two servo motors and different actuation inputs are also designed to realize forward, backward, leftturn and right-turn motion patterns. In addition, the robot has integrated micro-controller, signal receiver and other electronic components to enable remote control. Experimental results show that the realized robot can successfully achieve flexible straight-line and turning motions, which verifies the feasibility of topology optimized soft legs for creating walking robots.

Earthquake and other disasters nowadays still threat people’s lives and property due to their destructiveness and unpredictability. The past decades have seen the booming development of search and rescue robots due to their potential for increasing rescue capacity as well as reducing personnel safety risk at disaster sites. In this work, we propose a spider-inspired wheeled compliant leg to further improve the environmental adaptability of search mobile robots. Different from the traditional fully-actuated method with independent motor joint control, this leg employs an under-actuated compliant mechanism design with overall semi-tendon-driven control, which enables the passive and active terrain adaptation, system simplification and lightweight of the realized search robot. We have generalized the theoretical model and design methodology for this type of compliant leg, and implement it in a parametric program to improve the design efficiency. In addition, preliminary load capacity and leg-lifting experiments are carried out on a one-leg prototype to evaluate its mechanical performance. A four-legged robot platform is also fabricated for the locomotion tests. The preliminary experimental results have verified the feasibility of the proposed design methodology, and also show possibilities for improvements. In future work, structural optimization and stronger actuation elements should be introduced to further improve the mechanical performance of the fabricated wheeled leg mechanism and robot platform.

In the dynamic and unstructured environment of human–robot symbiosis, companion robots require natural human–robot interaction and autonomous intelligence through multimodal information fusion to achieve effective collaboration. Nevertheless, the control precision and coordination of the accompanying actions are not satisfactory in practical applications. This is primarily attributed to the difficulties in the motion coordination between the accompanying target and the mobile robot. This paper proposes a companion control strategy based on the Linear Quadratic Regulator (LQR) to enhance the coordination and precision of robot companion tasks. This method enables the robot to adapt to sudden changes in the companion target’s motion. Besides, the robot could smoothly avoid obstacles during the companion process. Firstly, a human–robot companion interaction model based on nonholonomic constraints is developed to determine the relative position and orientation between the robot and the companion target. Then, an LQR-based companion controller incorporating behavioral dynamics is introduced to simultaneously avoid obstacles and track the companion target’s direction and velocity. Finally, various simulations and real-world human–robot companion experiments are conducted to regulate the relative position, orientation, and velocity between the target object and the robot platform. Experimental results demonstrate the superiority of this approach over conventional control algorithms in terms of control distance and directional errors throughout system operation. The proposed LQR-based control strategy ensures coordinated and consistent motion with target persons in social companion scenarios.

The ability to follow people can benefit the human-robot interaction of mobile robots. This work proposes a hybrid human tracking system for human following robots, integrating sensor fusion of Ultra-Wideband (UWB) and monocular visual positioning to enhance tracking accuracy and precision. At the same time, UWB and the visual positioning system can operate independently, thereby creating a redundancy in the system. Based on our previous study of UWB-positioning, this article elaborates on a visual positioning system that employs human detection using a pre-trained Convolutional Neural Network (CNN), coupled with data fusion process based on experimental assessments. The hybrid human tracking system achieves a 2D Euclidean accuracy RMS of 7.4 cm, demonstrating sufficient accuracy for human following and improving the following performance in real-world experiments compared to our previous study.

Quadruped robots are used for a wide variety of transportation and exploration tasks due to their high dexterity. Currently, many studies utilize soft robotic legs to replace rigid-link-based legs, with the aim to improve quadruped robots' adaptability to complex environments. However, the conventional soft legs still face the challenge of limited load-bearing capacity. To cope with this issue, we propose in this work a type of soft-rigid hybrid leg, which is synthesized by using a multistage topology optimization method. A simplified model is also created to describe the kinematics of the synthesized soft leg. Using the realized legs, we have developed a turtle-inspired quadruped robot called TurBot. By mimicking the walking pattern of a turtle, two motion gaits (straight-line walking and turning) are designed to realize the robotic locomotion. Experiments are also conducted to evaluate the walking performance of TurBot. Results show that the realized robot can achieve stable straight-line walking and turning motions. In addition, TurBot can carry up to 500 g extra weight while walking, which is 126% of its own body weight. Moreover, different locomotion tests have also successfully verified TurBot's ability to adapt to complex environments.

BACKGROUND:Inflammatory demyelinating diseases of the central nervous system, such as multiple sclerosis, are significant sources of morbidity in young adults despite therapeutic advances. Current murine models of remyelination have limited applicability due to the low white matter content of their brains, which restricts the spatial resolution of diagnostic imaging. Large animal models might be more suitable but pose significant technological, ethical and logistical challenges.METHODS:We induced targeted cerebral demyelinating lesions by serially repeated injections of lysophosphatidylcholine in the minipig brain. Lesions were amenable to follow-up using the same clinical imaging modalities (3T magnetic resonance imaging, 11C-PIB positron emission tomography) and standard histopathology protocols as for human diagnostics (myelin, glia and neuronal cell markers), as well as electron microscopy (EM), to compare against biopsy data from two patients.FINDINGS:We demonstrate controlled, clinically unapparent, reversible and multimodally trackable brain white matter demyelination in a large animal model. De-/remyelination dynamics were slower than reported for rodent models and paralleled by a degree of secondary axonal pathology. Regression modelling of ultrastructural parameters (g-ratio, axon thickness) predicted EM features of cerebral de- and remyelination in human data.INTERPRETATION:We validated our minipig model of demyelinating brain diseases by employing human diagnostic tools and comparing it with biopsy data from patients with cerebral demyelination.FUNDING:This work was supported by the DFG under Germany's Excellence Strategy within the framework of the Munich Cluster for Systems Neurology (EXC 2145 SyNergy, ID 390857198) and TRR 274/1 2020, 408885537 (projects B03 and Z01).

The study presents a new system for automating media exchange in cell cultures. This system is designed to fit inside common incubators and uses T75 flasks as growth vessels. It follows a step-by-step process, involving rotating and tilting mechanisms to drain old media, cleanse flask interiors, and refill with fresh media. The system's design incorporates a loading platform for four flasks, driven by a stepper motor and gear mechanism. Tilting is controlled by a servo motor, while a peristaltic pump refills with fresh media. Electronics, including an Arduino Nano, are sealed for protection. Sensors ensure flask presence and media condition. Validation involved 200 water-based cycles and successful fibroblast cell culture for eight days. The system shows potential for streamlining cell maintenance, although long-term durability and contamination concerns require further investigation.

Flexure-joint-based continuum robots are used in a variety of engineering applications, such as minimally invasive surgery and space exploration. However, some highly flexible joints, such as the leaf-spring joint, have a low torsional stiffness, which greatly limits the payload capacity of the constructed continuum robots in their curved configuration. On the other hand, some high-torsional-stiffness joints, such as the cartwheel joint, also suffer from the issue of stress concentration. To cope with these problems, in this article, we propose a 3-D-topology-optimization-based method in this article to achieve multiaxis design of flexure joints. Using a multiobjective algorithm, the torsional stiffness and rotational flexibility of different axes of the joint structure are taken into account in the optimization process. In addition, artificial spring elements are introduced in the design problem to realize a balanced stress distribution. To evaluate the feasibility of the proposed method, experiments are also performed to test the bending performance and torsional stiffness of the constructed continuum robot. Results have demonstrated that, the continuum robot equipped with the optimized flexure joints can successfully achieve high torsional stiffness while maintaining its bending flexibility.