Soft roboticsPub Date : 2025-05-26DOI: 10.1089/soro.2024.0157
Ki-Young Song, Wenjun Zhang
{"title":"Bioinspired Design for Energy-Efficient Soft Actuators Achieving Asymmetrical Spatiotemporal Deformation.","authors":"Ki-Young Song, Wenjun Zhang","doi":"10.1089/soro.2024.0157","DOIUrl":"https://doi.org/10.1089/soro.2024.0157","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144176400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-08DOI: 10.1089/soro.2024.0079
Chenlong Tang, Hui Ma, Shiyu Wu, Hui Zhang, Wenquan Chen, Yang Zhou, Kun Wei, Xiaojian Li, Fuzhou Niu, Ping Liu, Yuping Duan, Guangli Liu, Tingting Luo, Runhuai Yang
{"title":"Customizable Single-Layer Programmable Deformation Hydrogel Robots Based on One-Time Fabricating with Near-Infrared-Triggered Responsiveness.","authors":"Chenlong Tang, Hui Ma, Shiyu Wu, Hui Zhang, Wenquan Chen, Yang Zhou, Kun Wei, Xiaojian Li, Fuzhou Niu, Ping Liu, Yuping Duan, Guangli Liu, Tingting Luo, Runhuai Yang","doi":"10.1089/soro.2024.0079","DOIUrl":"https://doi.org/10.1089/soro.2024.0079","url":null,"abstract":"<p><p>Programmable deformation hydrogel robots have garnered significant attention in biomedical fields due to their ability to undergo large-scale reversible deformation. As clinical demand rises, there is a need for hydrogel robots that are easy to process and operate, and can undergo programmable deformation. Here, we propose a method to fabricate single-layer programmable deformation hydrogel robots in one step using a high-precision digital light processing 3D printing system. Two kinds of deformable elements with different structure distribution on the top and bottom sides are produced by using two kinds of focused light with varying intensities. By combining these deformable elements, we create four basic modules with different and fixed deformable shapes. The desired shape deformation in hydrogel robots can be achieved by programming the combination of these four basic modules. The hydrogel robots exhibit reversible repeat deformation under near-infrared light stimulation. We validate our approach by fabricating several scaffolds using combinations of the four basic modules, demonstrating the feasibility of programming deformation and the potential application of these scaffolds in pipeline movement. This research provides the feasibility for the simple programming deformation of hydrogel robots and offers a novel approach for fabricating programmable deformation hydrogel robots in biomedical fields.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143805275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2025-01-06DOI: 10.1089/soro.2024.0025
Chaeree Park, Hyunkyu Park, Jung Kim
{"title":"Unsupervised Sim-to-Real Adaptation of Soft Robot Proprioception Using a Dual Cross-Modal Autoencoder.","authors":"Chaeree Park, Hyunkyu Park, Jung Kim","doi":"10.1089/soro.2024.0025","DOIUrl":"10.1089/soro.2024.0025","url":null,"abstract":"<p><p>Data-driven calibration methods have shown promising results for accurate proprioception in soft robotics. This process can be greatly benefited by adopting numerical simulation for computational efficiency. However, the gap between the simulated and real domains limits the accurate, generalized application of the approach. Herein, we propose an unsupervised domain adaptation framework as a data-efficient, generalized alignment of these heterogeneous sensor domains. A dual cross-modal autoencoder was designed to match the sensor domains at a feature level without any extensive labeling process, facilitating the computationally efficient transferability to various tasks. Moreover, our framework integrates domain adaptation with anomaly detection, which endows robots with the capability for external collision detection. As a proof-of-concept, the methodology was adopted for the famous soft robot design, a multigait soft robot, and two fundamental perception tasks for autonomous robot operation, involving high-fidelity shape estimation and collision detection. The resulting perception demonstrates the digital-twinned calibration process in both the simulated and real domains. The proposed design outperforms the existing prevalent benchmarks for both perception tasks. This unsupervised framework envisions a new approach to imparting embodied intelligence to soft robotic systems via blending simulation.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"213-227"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142934208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2024-09-30DOI: 10.1089/soro.2023.0028
Jihun Kim, Kimoon Nam, Seungtae Yang, Junyoung Moon, Jaeha Yang, Jaewook Ryu, Giuk Lee
{"title":"Improved Assistive Profile Tracking of Exosuit by Considering Adaptive Stiffness Model and Body Movement.","authors":"Jihun Kim, Kimoon Nam, Seungtae Yang, Junyoung Moon, Jaeha Yang, Jaewook Ryu, Giuk Lee","doi":"10.1089/soro.2023.0028","DOIUrl":"10.1089/soro.2023.0028","url":null,"abstract":"<p><p>Wearable robots have been developed to assist the physical performance of humans. Specifically, exosuits have attracted attention due to their lightweight and soft nature, which facilitate user movement. Although several types of force controllers have been used in exosuits, it is challenging to control the assistive force due to the material's softness. In this study, we propose three methods to improve the performance of the basic controller using an admittance-based force controller. In method A, the cable was controlled according to the user's thigh motion to eliminate delays in generating the assistive force and improve the control accuracy. In method B, the stiffness feedforward model of the human exosuit was divided into two independent models based on the assistance phase for compensating the nonlinear stiffness more accurately. In method C, the real-time optimization method for the stiffness feedforward model with an adaptive moment estimation method optimizer was proposed. To validate these methods' effectiveness, we designed three new controllers, gradually combined the proposed methods with the basic controller, and compared their performances. We found that controller III, combining all three methods with the basic controller, showed the best performance. By applying controller III in the same exosuit, the root-mean-square error of the assistive force decreased from 39.84 N to 13.72 N, reducing the error by 65.56% compared with the basic controller. Moreover, the time delay for force generation in the gait cycle percentage decreased from 9.99% to 3.41%, reducing the delay by 65.87% compared with the basic controller.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"200-212"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142335499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2024-10-28DOI: 10.1089/soro.2024.0030
Nana Obayashi, Kai Junge, Parth Singh, Josie Hughes
{"title":"Online Hydraulic Stiffness Modulation of a Soft Robotic Fish Tail for Improved Thrust and Efficiency.","authors":"Nana Obayashi, Kai Junge, Parth Singh, Josie Hughes","doi":"10.1089/soro.2024.0030","DOIUrl":"10.1089/soro.2024.0030","url":null,"abstract":"<p><p>This paper explores online stiffness modulation within a single tail stroke for swimming soft robots. Despite advances in stiffening mechanisms, little attention has been given to dynamically adjusting stiffness in real-time, presenting a challenge in developing mechanisms with the requisite bandwidth to match tail actuation. Achieving an optimal balance between thrust and efficiency in swimming soft robots remains elusive, and the paper addresses this challenge by proposing a novel mechanism for independent stiffness control, leveraging fluid-driven stiffening within a patterned pouch. Inspired by fluidic-driven actuation, this approach exhibits high bandwidth and facilitates significant stiffness changes. We perform experiments to demonstrate how this mechanism enhances both thrust and swimming efficiency. The tail actuation and fluid-driven stiffening can be optimized for a specific combination of thrust and efficiency, tailored to the desired maneuver type. The paper further explores the complex interaction between the soft body and surrounding fluid and provides fluid dynamics insights gained from the vortices created during actuation. Through frequency modulation and online stiffening, the study extends the Pareto front of achievable thrust generation and swimming efficiency.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"242-252"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142515635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reconfigurable, Transformable Soft Pneumatic Actuator with Tunable Three-Dimensional Deformations for Dexterous Soft Robotics Applications.","authors":"Dickson Chiu Yu Wong, Mingtan Li, Shijie Kang, Lifan Luo, Hongyu Yu","doi":"10.1089/soro.2023.0072","DOIUrl":"10.1089/soro.2023.0072","url":null,"abstract":"<p><p>Numerous soft actuators based on pneumatic network (PneuNet) design have already been proposed and extensively employed across various soft robotics applications in recent years. Despite their widespread use, a common limitation of most existing designs is that their action is predetermined during the fabrication process, thereby restricting the ability to modify or alter their function during operation. To address this shortcoming, in this article the design of a Reconfigurable, Transformable Soft Pneumatic Actuator (RT-SPA) is proposed. The working principle of the RT-SPA is analogous to the conventional PneuNet. The key distinction between the two lies in the ability of the RT-SPA to undergo controlled transformations, allowing for more versatile bending and twisting motions in various directions. Furthermore, the unique reconfigurable design of the RT-SPA enables the selection of actuation units with different sizes to achieve a diverse range of three-dimensional deformations. This versatility enhances the RT-SPA's potential for adaptation to a multitude of tasks and environments, setting it apart from traditional PneuNet. The article begins with a detailed description of the design and fabrication of the RT-SPA. Following this, a series of experiments are conducted to evaluate the performance of the RT-SPA. Finally, the abilities of the RT-SPA for locomotion, gripping, and object manipulation are demonstrated to illustrate the versatility of the RT-SPA across different aspects.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"228-241"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142305264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2024-12-11DOI: 10.1089/soro.2023.0073
Zhenchao Ling, Aihu Jia, Yunlong Fu, David T Branson, Zhibin Song, Jiayao Ma, Jian S Dai, Rongjie Kang
{"title":"Fluidic Oscillation-Based Pneumatic Actuation for Soft Locomotion and Grasping.","authors":"Zhenchao Ling, Aihu Jia, Yunlong Fu, David T Branson, Zhibin Song, Jiayao Ma, Jian S Dai, Rongjie Kang","doi":"10.1089/soro.2023.0073","DOIUrl":"10.1089/soro.2023.0073","url":null,"abstract":"<p><p>Most pneumatic actuators used in robotics are controlled by valves that contain moving parts (e.g., spool or rotor) and electronics to change the direction or pressure of the air flow. Thus, the dynamic bandwidth and robustness of the system are limited by these elements. This article presents an oscillation-based pneumatic actuation method to remove the moving parts and electronics from the valve. The obtained bistable load-switched (LoS) oscillator utilizes two output attachment walls to generate the Coanda effect and internal flow field to control the pressure in different output channels. The bistable LoS oscillator is implemented on a soft fish and runner, achieving locomotion speed up to 1.68 and 1.97 BL/s (body length per second), respectively, which are faster than existing counterparts. Furthermore, a single-output LoS oscillator is demonstrated by slightly modifying the bistable one. It enables the development of a soft runner with higher load capacity, as well as a relief valve used for pressure regulation in soft robotic grippers. The presented actuation methods can be potentially extended to a variety of situations that require compact size, light weight, high dynamics, and robustness.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"290-301"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2024-09-17DOI: 10.1089/soro.2023.0182
Nam Gyun Kim, Nikita J Greenidge, Joshua Davy, Shinwoo Park, James H Chandler, Jee-Hwan Ryu, Pietro Valdastri
{"title":"External Steering of Vine Robots via Magnetic Actuation.","authors":"Nam Gyun Kim, Nikita J Greenidge, Joshua Davy, Shinwoo Park, James H Chandler, Jee-Hwan Ryu, Pietro Valdastri","doi":"10.1089/soro.2023.0182","DOIUrl":"10.1089/soro.2023.0182","url":null,"abstract":"<p><p>This article explores the concept of external magnetic control for vine robots to enable their high curvature steering and navigation for use in endoluminal applications. Vine robots, inspired by natural growth and locomotion strategies, present unique shape adaptation capabilities that allow passive deformation around obstacles. However, without additional steering mechanisms, they lack the ability to actively select the desired direction of growth. The principles of magnetically steered growing robots are discussed, and experimental results showcase the effectiveness of the proposed magnetic actuation approach. We present a 25-mm-diameter vine robot with an integrated magnetic tip capsule, including 6 degrees of freedom (DOF) localization system and camera, and demonstrate a minimum bending radius of 3.85 cm with an internal pressure of 30 kPa. Furthermore, we evaluate the robot's ability to form tight curvature through complex navigation tasks, with magnetic actuation allowing for extended free-space navigation without buckling. The suspension of the magnetic tip was also validated using the 6 DOF localization system to ensure that the shear-free nature of vine robots was preserved. Additionally, by exploiting the magnetic wrench at the tip, we showcase preliminary results of vine retraction. The findings contribute to the development of controllable vine robots for endoluminal applications, providing high tip force and shear-free navigation.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"159-170"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12021788/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142305263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2024-10-22DOI: 10.1089/soro.2023.0067
Yang Qu, Yiming Zhang, Boyuan Huang, Cheng Chen, Huacen Wang, Sicong Liu, Hongqiang Wang
{"title":"Pump-Free Pneumatic Actuator Driven by the Vapor Pressure at the Gas-Liquid Equilibrium of Aqua Ammonia.","authors":"Yang Qu, Yiming Zhang, Boyuan Huang, Cheng Chen, Huacen Wang, Sicong Liu, Hongqiang Wang","doi":"10.1089/soro.2023.0067","DOIUrl":"10.1089/soro.2023.0067","url":null,"abstract":"<p><p>Currently, pneumatic soft actuators are widely used due to their impressive adaptability, but they still face challenges for more extensive practical applications. One of the primary issues is the bulky and noisy air compressors required to generate air pressure. To circumvent this critical problem, this work proposes a new type of air pressure source, based on the vapor pressure at the gas-liquid equilibrium to replace conventional air pumps. Compared with the previous phase transition method, this approach gains advantages such as generating gas even at low temperatures (instead of boiling point), more controllable gas output, and higher force density (since both ammonia and water contribute to the gas pressure). This work built mathematical models to explain the mechanism of converting energy to output action force from electrical energy and found the aqua ammonia system is one of the optimal choices. Multiple prototypes were created to demonstrate the capability of this method, including a pouch actuator that pushed a load 20,555 times heavier than its dead weight. Finally, based on the soft actuator, an untethered crawling robot was implemented with onboard batteries, showing the potentially extensive applications of this methodology.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"171-182"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft roboticsPub Date : 2025-04-01Epub Date: 2024-12-13DOI: 10.1089/soro.2023.0029
Jens Reinecke, Bastian Deutschmann, Alexander Dietrich, Simon R Eugster, Marco Hutter
{"title":"A Computational Approach for Internal Tendon Routing Channels in a Tendon-Driven Continuum Joint.","authors":"Jens Reinecke, Bastian Deutschmann, Alexander Dietrich, Simon R Eugster, Marco Hutter","doi":"10.1089/soro.2023.0029","DOIUrl":"10.1089/soro.2023.0029","url":null,"abstract":"<p><p>Tendon-driven continuum soft robots are currently applied in research and are given a promising perspective for future applications. For the routing of the tendons from the actuator to the point where the loading is demanded, two routing possibilities exist in the literature: internal routing of the tendons with the help of structurally embedded Bowden sheaths and external tendon routing where the tendon is not in contact with the soft structure. The application of the latter is a clear disadvantage for applications due to the high risk of interference with the tendon, for example, causing the tendon to break. The first option on the other hand introduces high friction forces into the tendon transmission and affects the elastic characteristic of the continuum and therefore the desired workspace of the system. This article overcomes the aforementioned problems by integrating tendon routings within tendon channels eroded from the continuum structure by a model-based design method. The channels within the continuum structure are computed <i>a priori</i> such that the tendons do not interact with the continuum while moving through its workspace. Overall, a new model-based method for tendon channel design is introduced and a corresponding manufacturing process is established. A continuum joint module prototype is designed to enable roll-pitch-yaw motions with a large accessible workspace. The capabilities of the system are measured in experiments using an external camera for the range of motion. Moreover, walking experiments on the ANYmal robot from ETHZ are presented.</p>","PeriodicalId":94210,"journal":{"name":"Soft robotics","volume":" ","pages":"280-289"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142820481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}