Soft Electrically Actuated Quadruped (SEAQ)—Integrating a Flex Circuit Board and Elastomeric Limbs for Versatile Mobility

Huang, Xiaonan; Kumar, Kitty; Jawed, Mohammad; Ye, Zisheng; Majidi, Carmel

doi:10.1109/lra.2019.2903856

Cited by 35 publications

(16 citation statements)

References 42 publications

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“…The fabrication process is similar to the one presented in refs. 42,46 . We start the fabrication process by laser-cutting two pieces of thermally conductive tape (H48-2, T-Global) with dimensions of 40 × 18 × 0.5 mm (55 × 18 × 0.5 mm for the jumping robot) and 80 × 55 × 0.5 mm by a CO 2 laser-cutting system (30 W VLS 3.50; Universal Laser Systems).…”

Section: Methodsmentioning

confidence: 99%

Dynamic simulation of articulated soft robots

Huang

Majidi

et al. 2020

Nat Commun

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Soft robots are primarily composed of soft materials that can allow for mechanically robust maneuvers that are not typically possible with conventional rigid robotic systems. However, owing to the current limitations in simulation, design and control of soft robots often involve a painstaking trial. With the ultimate goal of a computational framework for soft robotic engineering, here we introduce a numerical simulation tool for limbed soft robots that draws inspiration from discrete differential geometry based simulation of slender structures. The simulation incorporates an implicit treatment of the elasticity of the limbs, inelastic collision between a soft body and rigid surface, and unilateral contact and Coulombic friction with an uneven surface. The computational efficiency of the numerical method enables it to run faster than real-time on a desktop processor. Our experiments and simulations show quantitative agreement and indicate the potential role of predictive simulations for soft robot design.

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Section: Methodsmentioning

confidence: 99%

Dynamic simulation of articulated soft robots

Huang

Majidi

et al. 2020

Nat Commun

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“…It is able to change reversibly between an unactuated soft curled shape and an actuated rigid straightened shape ( Figure 1B ). Previously, it was shown that flexural SMA actuators could enable an untethered soft quadruped (SEAQ) to walk with a maximum speed of 0.56 body lengths per second ( Huang et al, 2019b ). However, SEAQ did not contain any sensors to track actuator relaxation and the limbs were instead cyclically activated using a fixed cooling time.…”

Section: Introductionmentioning

confidence: 99%

“…Because nitinol is conductive, this phase transition can be induced through Joule (Ohmic) heating by applying voltage and passing current through the actuator. In this way, SMA has been used for actuation in a large number of soft robotic systems ( Lin et al, 2011 ; Jin et al, 2016a ; Huang et al, 2018 , Huang et al, 2019b ; Li et al, 2019 ). However, while promising for these implementations, more widespread application of SMA for robotic actuation is limited by challenges with thermal management and control.…”

Section: Introductionmentioning

confidence: 99%

Shape Memory Alloy (SMA) Actuator With Embedded Liquid Metal Curvature Sensor for Closed-Loop Control

et al. 2021

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We introduce a soft robot actuator composed of a pre-stressed elastomer film embedded with shape memory alloy (SMA) and a liquid metal (LM) curvature sensor. SMA-based actuators are commonly used as electrically-powered limbs to enable walking, crawling, and swimming of soft robots. However, they are susceptible to overheating and long-term degradation if they are electrically stimulated before they have time to mechanically recover from their previous activation cycle. Here, we address this by embedding the soft actuator with a capacitive LM sensor capable of measuring bending curvature. The soft sensor is thin and elastic and can track curvature changes without significantly altering the natural mechanical properties of the soft actuator. We show that the sensor can be incorporated into a closed-loop “bang-bang” controller to ensure that the actuator fully relaxes to its natural curvature before the next activation cycle. In this way, the activation frequency of the actuator can be dynamically adapted for continuous, cyclic actuation. Moreover, in the special case of slower, low power actuation, we can use the embedded curvature sensor as feedback for achieving partial actuation and limiting the amount of curvature change.

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“…The mobile soft robots in literature generally make use of either shape memory alloys [3]- [8] or pneumatic actuators [9]- [11] for actuation. Some robots even use combustion for actuation [12], but it brings the need of storing combustible gases and carrying a component for ignition.…”

Section: Introductionmentioning

confidence: 99%

“…Some specific works like sensors [13] or exoskeletons [14] can be fully soft; but only a sole example can be seen as a fully soft robot [15]. SEAQ [3] is one of the few examples of an untethered soft robot, which utilizes a soft body and soft legs together, however the use of high power shape memory alloys limit the operation time considerably. Most of the examples in soft robot literature are tethered, more so in the miniature scale, as it's significantly difficult to create a fully soft robot that is both untethered and mobile; regarding the states of technology and soft robotics research.…”

Section: Introductionmentioning

confidence: 99%

Design, Fabrication, and Locomotion Analysis of an Untethered Miniature Soft Quadruped, SQuad

Kalın

Aygül

Türkmen

et al. 2020

IEEE Robot. Autom. Lett.

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The conventional robotics, which involves utilization of robots made out of hard materials like metals and hard plastics, has helped humankind automate many different sorts of labor and such robots have been assisting the humans in various tasks. Nevertheless, some applications require very delicate interactions and adaptability of the robots to unstructured elements and obstacles; which can only be provided by softness. The miniature and untethered robot in this work is fully made out of soft structural materials and uses a flexible circuit board. Only the electronic components, actuators and several little connection parts are hard. Its soft legs, body, and circuit enables it to overcome obstacles that conventional hard miniature robots tend to be stopped by. For the soft robot presented, walking and obstacle climbing experiments were done and pitch angle, roll angle, robot's centroid position and stiffness analyses were conducted. Additionally, three other robots are fabricated in hard body-hard leg, hard body-soft leg, and soft body-hard leg configurations and the effects of body and leg compliance on the locomotion performance are investigated. The results show that a soft body-soft leg robot configuration can scale an obstacle 1.44 times its body height whereas the hard bodied and hard legged robot can only go over 0.88 times its body height. The results also indicate that the softness of the body effects the scalable obstacle height more than the softness of the legs at this length scale.

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Soft Electrically Actuated Quadruped (SEAQ)—Integrating a Flex Circuit Board and Elastomeric Limbs for Versatile Mobility

Cited by 35 publications

References 42 publications

Dynamic simulation of articulated soft robots

Dynamic simulation of articulated soft robots

Shape Memory Alloy (SMA) Actuator With Embedded Liquid Metal Curvature Sensor for Closed-Loop Control

Design, Fabrication, and Locomotion Analysis of an Untethered Miniature Soft Quadruped, SQuad

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