Article
Robotics
Junfeng Hu, Long Liang, Bin Zeng
Summary: This paper presents a novel soft actuator with stiffness variation using particulate jamming technology. The influence factors of stiffness variation and the dependence of granular attributes on stiffness were analyzed. The experimental results showed that the structural parameters have significant effect on the bending angle, but little effect on the end force.
Article
Engineering, Multidisciplinary
Yu Shan, Yanzhi Zhao, Changlei Pei, Hongnian Yu, Pengcheng Liu
Summary: This paper proposes and designs a passive variable stiffness soft robotic gripper using the principle of jamming to grasp objects in a simple and robust manner. The design principle and feasibility of the gripper are verified through experimental prototypes.
BIOINSPIRATION & BIOMIMETICS
(2022)
Article
Automation & Control Systems
Hwayeong Jeong, Jung Kim
Summary: The variable stiffness capability of soft robots combines adaptability with the ability to transmit large forces and high payloads in a rigid state, broadening the range of applications. Inspired by echinoderms, a stiffness-modulation method using a rigid structure reinforced with porous material actuated by vacuum was developed. The method demonstrated a continuous stiffness change (15-fold increase) and mechanical programmability. Applying this method to a gripper and robotic paw showcased the advantages of stiffness modulation in soft robotics.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Automation & Control Systems
Yegor Piskarev, Antoine Devincenti, Vivek Ramachandran, Pierre-Etienne Bourban, Michael D. Dickey, Jun Shintake, Dario Floreano
Summary: This article presents a soft gripper that combines granular jamming and electroadhesion to gently grasp and release objects with varying properties. It can operate in different modes to handle objects with different surface conditions and mechanical properties.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Robotics
Long Li, Fengming Xie, Tianhong Wang, Guopeng Wang, Yingzhong Tian, Tao Jin, Quan Zhang
Summary: This article presents a compact soft gripper with a variable stiffness module and a retractable mechanism for soft-rigid hybrid actuation. The gripper achieves high stiffness without sacrificing flexibility and demonstrates robustness and dexterity in versatile tasks.
Article
Robotics
Hang Wei, Yu Shan, Yanzhi Zhao, Lizhe Qi, Xilu Zhao
Summary: To address the lack of multidirectional grasping ability in soft grippers under inclination, researchers propose a novel variable stiffness module that combines rigid multidirectional loading with local variable stiffness. This allows for soft grasping and multidirectional rigid loading in a soft gripper. The stiffness control is achieved through a double-layer pneumatic driving structure with simple control and fast response. The prototype experiments verify the adaptability and stable grasping ability of the robot, and the variable stiffness increases the maximum grasping weight in each direction by more than three times.
IEEE TRANSACTIONS ON ROBOTICS
(2022)
Article
Robotics
Si-Qi An, Wen-Hao Li, Ji-Hui Li, Hai-Lin Zou, Zi-Chen Deng
Summary: Stiffness variation is crucial for enhancing load capacity and compliance of soft robots. Jamming methods, such as particle, layer, or fiber jamming, are widely used for achieving stiffness variation. However, it is still challenging to make the variable stiffness components lightweight and adaptive, and existing jamming mechanisms often face deformation-induced softening, limiting their applications in cases requiring both large deformation and high stiffness.
Article
Engineering, Electrical & Electronic
Siyuan Liu, Yuhang Bian, Chao Ai, Hongmei Sun, Yijie Deng, Zilong Chen, Xiaorui Chen, Jingtao Zhang
Summary: This paper proposes a new pneumatic modular joint that balances compliance and load-bearing capacity for soft robots. The joint allows for omnidirectional deformation and dynamically adjustable stiffness. Mathematical models, numerical analysis, finite element simulations, and experimental validation were conducted to study the deformation, stiffness, and coupling characteristics of the joint.
Article
Automation & Control Systems
Wenpei Zhu, Chenghua Lu, Qule Zheng, Zhonggui Fang, Haichuan Che, Kailuan Tang, Mingchao Zhu, Sicong Liu, Zheng Wang
Summary: Soft grippers with hybrid design, combining soft actuators and rigid constraints, have gained attention for their improved safety, dexterity, and adaptability. This work presents a new hybrid gripper design inspired by the human metacarpophalangeal (MCP) joint, featuring eight independent muscles. Experimental results demonstrate the novel features enabled by adding MCP complexity, such as in-hand manipulation and lateral passive compliance. The prototype gripper, utilizing lightweight pneumatic bellows soft actuators, achieves excellent grasping adaptability and can grasp objects over 20 times its weight.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Robotics
Fenglin Han, Lei Fei, Run Zou, Weijian Li, Jinghao Zhou, Haiming Zhao
Summary: This article presents the design, fabrication, and tests of a novel soft actuator with good restorability and compliance. Cotton threads were used to connect the spherical acrylic beads into form strings to improve the restorability of the actuator. Compressed air was used to drive the actuator and beads were injected into the actuator after active deformation to avoid the jamming effect. Pulling the threads allowed the actuator to be restored to the initial state with minimal error.
IEEE TRANSACTIONS ON ROBOTICS
(2023)
Article
Robotics
Jingyi Huang, Andre Rosendo
Summary: The article proposes a framework for variable-stiffness object recognition using tactile information collected by a soft gripper. The results show that the proposed method excels in distinguishing 3D shapes and sizes of objects and achieves a high recognition accuracy using a Naive Bayes classifier.
Article
Engineering, Electrical & Electronic
Tete Hu, Xinjiang Lu, Du Xu
Summary: For a good soft gripper, it is important to have multiple grasping modes, variable stiffness, and high load capacity. However, most existing soft grippers lack these features. Therefore, a novel enclosing soft robotic gripper is designed with two grasping modes, tunable stiffness, and high load capacity.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Computer Science, Information Systems
Hyeonjun Park, Myunghyun Kim, Bumjoo Lee, Donghan Kim
Summary: This paper introduces an anthropomorphic robot hand with variable grasping stiffness, achieved through variable impedance control for broader stiffness range. Parameter update is used to adjust impedance parameters, and the procedure for evaluating grasping capability of the robot hand is explained.
Article
Automation & Control Systems
Jae-Young Lee, Yong-Sin Seo, Chanhun Park, Je-Sung Koh, Uikyum Kim, Jongwoo Park, Hugo Rodrigue, Byeungin Kim, Sung-Hyuk Song
Summary: The universal soft gripper with shape-adaptive skin and stiffness transition feature can effectively grip complex-shaped fragile objects, preventing damage to the objects.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Automation & Control Systems
Junfeng Li, Jiahao Li, Zuqi Wu, YongAn Huang
Summary: In this article, a new soft finger is introduced that utilizes polycaprolactone and an integrated actuating-cooling system to achieve a fast variable stiffness mechanism. The finger demonstrates a significant 15-fold stiffness variation over a temperature range of 20°C to 60°C. The cycle time of the variable stiffness is much shorter when using the integrated actuating-cooling hydraulic system compared to the pneumatic method, and a Cosserat rod model is used to control the position and stiffness simultaneously.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)