Highly Dynamic Shape Memory Alloy Actuator for Fast Moving Soft Robots

Huang, Xiaonan; Kumar, Kitty; Jawed, Mohammad; Nasab, Amir Mohammadi; Ye, Zisheng; Shan, Wanliang; Majidi, Carmel

doi:10.1002/admt.201800540

Cited by 152 publications

(120 citation statements)

References 21 publications

(24 reference statements)

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“…A variety of actuation mechanisms have been employed to actuate bioinspired soft robots mimicking the flexibility and multiple degrees of freedom of their natural counterparts . Tendon‐based actuation using tension or shape memory alloy cables has proven to be effective in providing soft elastomeric tentacles and caterpillars with agile and rapid 3D motion . However, the speed of soft tendon‐actuated robots, due to the slow recovery of their elastomeric bodies, relies on their agonist–antagonist configuration .…”

Section: Introductionmentioning

confidence: 99%

Elastic Energy Storage Enables Rapid and Programmable Actuation in Soft Machines

Pal

Goswami

Martínez

2019

Adv Funct Materials

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Storage of elastic energy is key to increasing the efficiency, speed, and power output of many biological systems. This paper describes a simple design strategy for the rapid fabrication of prestressed soft actuators (PSAs), exploiting elastic energy storage to enhance the capabilities of soft robots. The elastic energy that PSAs store in their prestressed elastomeric layer enables the fabrication of grippers capable of zero-power holding up to 100 times their weight and perching upside down from angles of up to 116°. The direction and magnitude of the force used to prestress the elastomeric layer can be controlled not only to define the final shape of the PSA but also to program its actuation sequence. Additionally, the release of the elastic energy stored by PSAs causes their high-speed recovery (≈50 ms), which significantly improves the actuation rates of soft pneumatic actuators, especially after motions requiring large deformations. Moreover, judicious prestressing of PSAs can also create bistable soft robotic systems, which use their stored elastic energy as a source of power amplification for rapid movements. These strategies serve as a basis for a new class of entirely soft robots capable of recreating bioinspired high-powered and high-speed motions using stored elastic energy.

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Section: Introductionmentioning

confidence: 99%

Elastic Energy Storage Enables Rapid and Programmable Actuation in Soft Machines

Pal

Goswami

Martínez

2019

Adv Funct Materials

View full text Add to dashboard Cite

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Section: Shape Memory Alloysmentioning

confidence: 99%

Materials as Machines

2020

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of responsive materials as machines is in robotics. The vision, leadership, and research of Bar-Cohen is seminal in both invigorating and focusing current-day research activities to develop responsive materials [2] and implement [3] them as lightweight, dexterous, and gentle (e.g., soft) robotic elements. In this spirit, this review exhaustively details the materials, the nature of their stimuli-response, and discusses considerations for their implementation in robotic systems and subsystems.Robotics is a well-established but growing field of research. Sustained progress in both performance and functionality continue to be realized in commercial robotic systems largely based on conventional materials and their integration with mechanisms. A recent example is the Atlas robot from Boston Dynamics [4] (Figure 1a). The incorporation of stimuli-responsive materials in robotics has largely focused on component-level demonstrations to extend the performance of a subsystem (such as a hand or gripper).Stimuli-responsive materials, spanning nearly all classes of materials and size scales, are currently subject to widespread examination in corporate, government, and academic research laboratories (Figure 1b-d). [5][6][7] In some cases, these materials have already found widespread commercial implementation in end use and are comparatively mature. The materials and fundamentals of their responses are summarized in Figure 2. Shape memory alloys (SMAs) and ceramic piezoelectric materials are distinctive in that they are hard, stimuli-responsive materials. Deformation of these materials can produce large energy densities due to their inherent stiffness. Electroactive polymers (EAPs) remain a topic of considerable interest, particularly dielectric elastomer actuators (DEAs). Engineered systems are rapidly emerging and enabling performance gains in robotics, largely based on pneumatic or fluidic (such as HASEL [8] actuators) transport processes that localize deformation to generate force or produce motion. Soft materials, such as shape memory polymers (SMPs), hydrogels, and liquid crystalline polymer networks (LCNs) and elastomers (LCEs) may offer distinctive functional performance to robotic systems in allowing local control of deformation without the need for complex interfacing with mechanisms. As will be evident, each of these materials has inherent advantages and performance tradeoffs that must be considered in functional implementations. However, responsive material systems have a common obstacle to widespread use: the performance and Machines are systems that harness input power to extend or advance function. Fundamentally, machines are based on the integration of materials with mechanisms to accomplish tasks-such as generating motion or lifting an object. An emerging research paradigm is the design, synthesis, and integration of responsive materials within or as machines. Herein, a particular focus is the integration of responsive materials to enable robotic (machine) functions such as gripping, lifting, or motility (walk...

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“…Despite these robots are very appealing, these robots involves with mismatch of two materials or an antagonistic or even more complex SMA wire design to realize periodic locomotion. For example, this robot introduce a prestrech layer to induce mismatch to create locomotion . Some soft robots consist of at least two SMA wires and two alternating stimuli signals to realize periodic locomotion.…”

Section: Introductionmentioning

confidence: 99%

A Periodic Deformation Mechanism of a Soft Actuator for Crawling and Grasping

Huang

2019

Adv Materials Technologies

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Periodic locomotion in nature has provided many inspirations for soft actuators. Compared with rigid actuators, soft actuators can transform into versatile shapes to adapt to different working environments and are able to interact with the human in a safer manner because of their compliance. However, soft actuators often suffer from complex structures designs and complicated sequences of stimuli to achieve periodic locomotion. To overcome this shortcoming, a periodic deformation mechanism based on strain energy storing is proposed in this paper. Guided by this mechanism, a simple soft actuator is designed without complicated control systems. The soft actuator involves shape memory alloy and silicon rubber. Crawling and grasping of the soft actuator are achieved by electrical heating methods. The proposed mechanism can provide inspiration for the design of soft actuators, smart wearable equipment, and medical devices.

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Highly Dynamic Shape Memory Alloy Actuator for Fast Moving Soft Robots

Cited by 152 publications

References 21 publications

Elastic Energy Storage Enables Rapid and Programmable Actuation in Soft Machines

Elastic Energy Storage Enables Rapid and Programmable Actuation in Soft Machines

Materials as Machines

A Periodic Deformation Mechanism of a Soft Actuator for Crawling and Grasping

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