Precharged Pneumatic Soft Actuators and Their Applications to Untethered Soft Robots

Soft Robotics ◽  
2018 ◽  
Vol 5 (5) ◽  
pp. 567-575 ◽  
Author(s):  
Yunquan Li ◽  
Yonghua Chen ◽  
Tao Ren ◽  
Yingtian Li ◽  
Shiu hong Choi
Keyword(s):  
Soft Robots ◽  
Soft Actuators

scholarly journals Dragonfly Inspired Smart Soft Robot

2020 ◽  
Author(s):  
Vardhman Kumar ◽  
Ung Hyun Ko ◽  
Yilong Zhou ◽  
Jiaul Hoque ◽  
Gaurav Arya ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Stimuli Responsive ◽  
Complex Environments ◽  
Soft Robots ◽  
Responsive Materials ◽  
Environmental Perturbations ◽  
Integration Strategies ◽  
Soft Actuators ◽  
Harsh Conditions

Recent advancements in soft robotics have led to the development of compliant robots that can exhibit complex motions driven by living cells(1, 2), chemical reactions(3), or electronics(4). Further innovations are however needed to create the next generation of soft robots that can carry out advanced functions beyond locomotion. Here we describe DraBot—a dragonfly-inspired, entirely soft, multifunctional robot that combines long-term locomotion over water surface with sensing, responding, and adaptation capabilities. By integrating soft actuators, stimuli-responsive materials, and microarchitectural features, we created a circuitry of pneumatic and microfluidic logic that enabled the robot to undergo user- and environment-controlled (pH) locomotion, including navigating hazardous (acidic) conditions. DraBot was also engineered to sense additional environmental perturbations (temperature) and detect and clean up chemicals (oil). The design, fabrication, and integration strategies demonstrated here pave a way for developing futuristic soft robots that can acclimatize and adapt to harsh conditions while carrying out complex tasks such as exploration, environmental remediation, and health care in complex environments.

scholarly journals Review of machine learning methods in soft robotics

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246102
Author(s):  
Daekyum Kim ◽  
Sang-Hun Kim ◽  
Taekyoung Kim ◽  
Brian Byunghyun Kang ◽  
Minhyuk Lee ◽  
...  
Keyword(s):  
Machine Learning ◽  
Soft Materials ◽  
Research Field ◽  
Machine Learning Techniques ◽  
Learning Approaches ◽  
Learning Methods ◽  
Soft Robots ◽  
Machine Learning Methods ◽  
Wearable Robots ◽  
Soft Actuators

Soft robots have been extensively researched due to their flexible, deformable, and adaptive characteristics. However, compared to rigid robots, soft robots have issues in modeling, calibration, and control in that the innate characteristics of the soft materials can cause complex behaviors due to non-linearity and hysteresis. To overcome these limitations, recent studies have applied various approaches based on machine learning. This paper presents existing machine learning techniques in the soft robotic fields and categorizes the implementation of machine learning approaches in different soft robotic applications, which include soft sensors, soft actuators, and applications such as soft wearable robots. An analysis of the trends of different machine learning approaches with respect to different types of soft robot applications is presented; in addition to the current limitations in the research field, followed by a summary of the existing machine learning methods for soft robots.

Modeling, Analysis, and Function Extension of the McKibben Hydraulic Artificial Muscles

2020 ◽  
Author(s):  
Siqing Chen ◽  
He Xu
Keyword(s):  
High Pressure ◽  
Theoretical Analysis ◽  
Artificial Muscle ◽  
Design Parameters ◽  
Artificial Muscles ◽  
Soft Robots ◽  
The Law ◽  
Soft Actuators ◽  
The Impact ◽  
The Relationship

Abstract Compared with rigid robots, flexible robots have soft and extensible bodies enforcing their abilities to absorb shock and vibration, hence reducing the impact of probable collisions. Due to their high adaptability and minimally invasive features, soft robots are used in various fields. The McKibben hydraulic artificial muscles are the most popular soft actuator because of the controllability of hydraulic actuator and high force to weight ratio. When its deformation reaches a certain level, the actuators can be stopped automatically without any other braking mechanism. The research of McKibben hydraulic artificial muscles is beneficial to the theoretical analysis of soft actuators in the mechanical system. The design of soft actuators with different deformations promotes the development of soft robots. In this paper, a static modeling of the McKibben hydraulic artificial muscles is established, and its correctness is verified by theoretical analysis and experiment. In this model, the deformation mechanism of the artificial muscle and the law of output force is put forward. The relationship between muscle pressure, load, deformation, and muscle design parameters is presented through the mechanical analysis of the braid, elastic tube, and sealed-end. The law of the muscle deformation with high pressure is predicted. The reason for the muscle’s tiny elongation with extremely high pressure is found through the analysis of the relationship between the angle of the braid, the length of single braided thread, and the pressure. With the increase of pressure, the angle of the braid tends to a fixed value. As the stress of braided thread increases, so does its length. The length changes obviously when the stress is extremely enormous. The angle of the braid and the length of the braided thread control the deformation of artificial muscles, resulting in a slight lengthening with extreme high pressure. Under normal pressure, the length of the braided wire is negligible, so that the entire muscle becomes shorter. According to the modeling and theoretical analysis, a new McKibben hydraulic artificial muscle that can elongate under normal rising pressure is designed. This artificial muscle can grow longer with pressure increases, eventually reaching its maximum length. During this time, its diameter barely changes. Its access pressure is higher than that of conventional elongated artificial muscles. Through experiments, the relationship between the muscle deformation, pressure, and load still conform to this theoretical model. This model can be used for the control of soft actuators and the design of new soft robots. This extensional McKibben hydraulic artificial muscles and the conventional McKibben hydraulic artificial muscles can be used in the bilateral control of soft robots.

scholarly journals Contactless Manipulation of Soft Robots

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3065 ◽  
Author(s):  
Kim ◽  
Park ◽  
Won ◽  
Jeon ◽  
Wie
Keyword(s):  
Recent Progress ◽  
Polymeric Materials ◽  
Anisotropic Materials ◽  
Robotic Systems ◽  
Soft Robots ◽  
Mechanical Joints ◽  
Potential Applications ◽  
Soft Actuators ◽  
External Stimuli ◽  
The Given

In recent years, jointless soft robots have demonstrated various curvilinear motions unlike conventional robotic systems requiring complex mechanical joints and electrical design principles. The materials employed to construct soft robots are mainly programmable anisotropic polymeric materials to achieve contactless manipulation of miniaturized and lightweight soft robots through their anisotropic strain responsivity to external stimuli. Although reviews on soft actuators are extensive, those on untethered soft robots are scant. In this study, we focus on the recent progress in the manipulation of untethered soft robots upon receiving external stimuli such as magnetic fields, light, humidity, and organic solvents. For each external stimulus, we provide an overview of the working principles along with the characteristics of programmable anisotropic materials and polymeric composites used in soft robotic systems. In addition, potential applications for untethered soft robots are discussed based on the physicochemical properties of programmable anisotropic materials for the given external stimuli.

scholarly journals Underwater Crawling Robot With Hydraulic Soft Actuators

2021 ◽  
Vol 8 ◽  
Author(s):  
Qinlin Tan ◽  
Yishan Chen ◽  
Jianhui Liu ◽  
Kehan Zou ◽  
Juan Yi ◽  
...  
Keyword(s):  
Weight Ratio ◽  
Vital Role ◽  
Soft Robots ◽  
Actuation System ◽  
Structural Rigidity ◽  
Hybrid Mechanism ◽  
Peristaltic Pumps ◽  
Motion Range ◽  
Soft Actuators ◽  
Leg Design

Benthic operation plays a vital role in underwater applications, where crawling robots have advantages compared with turbine-based underwater vehicles, in locomotion accuracy, actuation efficiency, current resistance, and in carrying more payloads. On the other hand, soft robots are quickly trending in underwater robotic design, with their naturally sealed body structure and intrinsic compliance both desirable for the highly unstructured and corrosive underwater environment. However, the limitations resulting directly from the inherent compliance, in structural rigidity, actuation precision, and limited force exertion capability, have also restricted soft robots in underwater applications. To date soft robots are adopted mainly as grippers and manipulators for atraumatic sampling, rather than as locomotion platforms. In this work, we present a soft-robotic approach to designing underwater crawling robots, with three main innovations: 1) using rigid structural components to strategically reinforce the otherwise omni-directionally flexible soft actuators, drastically increasing their loading capability and actuation precision; 2) proposing a rigid–soft hybrid multi-joint leg design, with quasi-linear motion range and force exertion, while maintaining excellent passive impact compliance by exploiting the inherent flexibility of soft actuators; 3) developing a novel valve-free hydraulic actuation system with peristaltic pumps, achieving a compact, lightweight, and untethered underwater crawling robot prototype with a 5:1 payload-to-weight ratio and multi-gait capability. The prototype was tested for design verification and showcasing the advantages of the proposed hybrid mechanism and actuation approach.

scholarly journals One Soft Step: Bio-Inspired Artificial Muscle Mechanisms for Space Applications

2022 ◽  
Vol 8 ◽  
Author(s):  
Joseph Ashby ◽  
Samuel Rosset ◽  
E.-F. Markus Henke ◽  
Iain A. Anderson
Keyword(s):  
Outer Space ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Space Applications ◽  
Soft Robots ◽  
Deformable Bodies ◽  
Low Mass ◽  
Soft Actuators ◽  
The Cost ◽  
High Work

Soft robots, devices with deformable bodies and powered by soft actuators, may fill a hitherto unexplored niche in outer space. All space-bound payloads are heavily limited in terms of mass and volume, due to the cost of launch and the size of spacecraft. Being constructed from stretchable materials allows many possibilities for compacting soft robots for launch and later deploying into a much larger volume, through folding, rolling, and inflation. This morphability can also be beneficial for adapting to operation in different environments, providing versatility, and robustness. To be truly soft, a robot must be powered by soft actuators. Dielectric elastomer transducers (DETs) offer many advantages as artificial muscles. They are lightweight, have a high work density, and are capable of artificial proprioception. Taking inspiration from nature, in particular the starfish podia, we present here bio-inspired inflatable DET actuators powering low-mass robots capable of performing complex motion that can be compacted to a fraction of their operating size.

scholarly journals A Dual-origami  Design Enables the Quasi-sequential Deployment and Bending  Motion of Soft Robots and Grippers

2021 ◽  
Author(s):  
Woongbae Kim ◽  
Jaemin Eom ◽  
Kyujin Cho
Keyword(s):  
Fused Deposition Modeling ◽  
Low Cost ◽  
Robotic Systems ◽  
Soft Robots ◽  
Fused Deposition ◽  
Sealing Performance ◽  
Fluidic Actuators ◽  
Deposition Modeling ◽  
Soft Actuators ◽  
Design Guidance

Soft fluidic actuators produce continuous and life-like motions that are intrinsically safe, but current designs are not yet mature enough to enable large deployment with high force and low-cost fabrication methods. Here, soft fluidic actuators with two superimposed origami architectures are reported. Driven by a fluid input, the presented dual-origami soft actuators produce quasi-sequential deployment and bending motion that is guided by unsymmetric unfolding of low-stretchable origami components. The dominance between the deployment and bending can be shifted by varying the unfolding behavior, enabling pre-programming of the motion. The proposed origami-inspired soft actuators are directly fabricated by low-cost fused deposition modeling 3D-printing, and subjected to a heat treatment post-processing to enhance the fluid sealing performance. Finally, soft gripper applications are presented and they successfully demonstrate gripping tasks that each requires strength, delicacy, precision and dexterity. The dual-origami approach offers a design guidance for soft robots to embody grow-and-retract motion with a small initial form factor, promising for applications in next-generation soft robotic systems.

Effect of Fiber Angle Variation on Bending Behavior of Semi-Cylindrical Fiber-Reinforced Soft Actuator

2018 ◽  
Author(s):  
Anis Darmohammadi ◽  
Hamid Reza Naeimi ◽  
Mahdi Agheli
Keyword(s):  
Fiber Reinforced ◽  
Effective Parameters ◽  
Angle Variation ◽  
Soft Robots ◽  
Soft Actuator ◽  
Finite Element Software ◽  
Fiber Angle ◽  
Cylindrical Fiber ◽  
Bending Behavior ◽  
Soft Actuators

Soft robots are a specific type of robots that are made of elastomeric materials. A specific type of soft actuators (soft robots) are called fiber-reinforced soft actuators. Effective parameters in the motion of fiber-reinforced soft actuators are cross-section area, thickness of the actuator, number of threads wrapped around the actuator, angle of threads, and if the fiber is wrapped one-way or two-way. Some of these parameters are already studied by researchers in the field. In this research, the aim is to investigate the effect of the angle of the fiber on the motion of a semi-cylindrical fiber-reinforced soft actuator with an inextensible layer attached to its flat surface. This paper studies the behavior analysis of the actuator, which is modeled in a finite element software. The behavior of the actuator in terms of bending is then studied by changing the angle of the fiber wrapped around the outer surface of the actuator. Results show that the bending behavior of the actuator highly depends on the fiber angle. Simulation results are then validated with experiment. The results presented in this paper provides an instruction on how one can improve or optimize the bending workspace of the actuator as needed.

scholarly journals Designing Conformal Ferromagnetic Soft Actuators Using Extended Level Set Methods (X-LSM)

2020 ◽  
Author(s):  
Jiawei Tian ◽  
Xuanhe Zhao ◽  
Xianfeng David Gu ◽  
Shikui Chen
Keyword(s):  
Topology Optimization ◽  
Objective Function ◽  
Level Set ◽  
Time Derivative ◽  
Level Set Methods ◽  
Soft Materials ◽  
Shape Sensitivity ◽  
Soft Robots ◽  
Soft Actuators ◽  
Material Layout

Abstract Ferromagnetic soft materials (FSM) can generate flexible movement and shift morphology in response to an external magnetic field. They have been engineered to design products in a variety of promising applications, such as soft robots, compliant actuators, or bionic devices, et al. By using different patterns of magnetization in the soft elastomer matrix, ferromagnetic soft matters can achieve various shape changes. Although many magnetic soft robots have been designed and fabricated, they are limited by the designers’ intuition. Topology optimization (TO) is a systematically mathematical method to create innovative structures by optimizing the material layout within a design domain without relying on the designers’ intuition. It can be utilized to architect ferromagnetic soft active structures. Since many of these ‘soft machines’ exist in the form of thin-shell structures, in this paper, the extended level set method (X-LSM) and conformal mapping theory are employed to carry out topology optimization of the ferromagnetic soft actuator on manifolds. The objective function consists of a sub-objective function for the kinematics requirement and a sub-objective function for minimum compliance. Shape sensitivity analysis is derived using the material time derivative and adjoint variable method. Two examples, including a circular shell actuator and a flytrap structure, are studied to demonstrate the effectiveness of the proposed framework.

scholarly journals A Dual-origami  Design Enables the Quasi-sequential Deployment and Bending  Motion of Soft Robots and Grippers

2021 ◽  
Author(s):  
Woongbae Kim ◽  
Jaemin Eom ◽  
Kyujin Cho
Keyword(s):  
Fused Deposition Modeling ◽  
Low Cost ◽  
Robotic Systems ◽  
Soft Robots ◽  
Fused Deposition ◽  
Sealing Performance ◽  
Fluidic Actuators ◽  
Deposition Modeling ◽  
Soft Actuators ◽  
Design Guidance

Soft fluidic actuators produce continuous and life-like motions that are intrinsically safe, but current designs are not yet mature enough to enable large deployment with high force and low-cost fabrication methods. Here, soft fluidic actuators with two superimposed origami architectures are reported. Driven by a fluid input, the presented dual-origami soft actuators produce quasi-sequential deployment and bending motion that is guided by unsymmetric unfolding of low-stretchable origami components. The dominance between the deployment and bending can be shifted by varying the unfolding behavior, enabling pre-programming of the motion. The proposed origami-inspired soft actuators are directly fabricated by low-cost fused deposition modeling 3D-printing, and subjected to a heat treatment post-processing to enhance the fluid sealing performance. Finally, soft gripper applications are presented and they successfully demonstrate gripping tasks that each requires strength, delicacy, precision and dexterity. The dual-origami approach offers a design guidance for soft robots to embody grow-and-retract motion with a small initial form factor, promising for applications in next-generation soft robotic systems.

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