Bio-inspired Tensegrity Soft Modular Robots

Zappetti, Davide; Mintchev, Stefano; Shintake, Jun; Floreano, Dario

doi:10.1007/978-3-319-63537-8_42

Cited by 46 publications

(25 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If we were to design a mechanism that underwent complex and large deformations, it would be necessary to add many joints, with multiple degrees of freedom in each, and many members connecting them. We see this in robot design techniques such as tensegrity, [57][58][59][60][61][62][63] origami and kirigami, [64][65][66][67][68][69] and modular systems, [70][71][72] which are also very interesting. As an alternative, soft polymer foams allow for more continuum-like behavior.…”

Section: ) Large Elastic Deformationsmentioning

confidence: 99%

Design and Manufacturing of Tendon-Driven Soft Foam Robots

Kastor¹,

Mukherjee²,

Cohen³

et al. 2019

Robotica

View full text Add to dashboard Cite

SummaryA design and manufacturing method is described for creating a motor tendon–actuated soft foam robot. The method uses a castable, light, and easily compressible open-cell polyurethane foam, producing a structure capable of large (~70% strain) deformations while requiring low torques to operate (<0.2 N·m). The soft robot can change shape, by compressing and folding, allowing for complex locomotion with only two actuators. Achievable motions include forward locomotion at 13 mm/s (4.3% of body length per second), turning at 9◦/s, and end-over-end flipping. Hard components, such as motors, are loosely sutured into cavities after molding. This reduces unwanted stiffening of the soft body. This work is the first demonstration of a soft open-cell foam robot locomoting with motor tendon actuators. The manufacturing method is rapid (~30 min per mold), inexpensive (under $3 per robot for the structural foam), and flexible, and will allow a variety of soft foam robotic devices to be produced.

show abstract

Section: ) Large Elastic Deformationsmentioning

confidence: 99%

Design and Manufacturing of Tendon-Driven Soft Foam Robots

Kastor¹,

Mukherjee²,

Cohen³

et al. 2019

Robotica

View full text Add to dashboard Cite

show abstract

“…8,9 Recently, tensegrity structures 10 have been proposed as an approach to design soft robots with mechanical properties similar to those of biological systems at different scales, ranging from individual cells 11 to muscular-skeletal systems. 12 Examples of such tensegrity systems include robots with embodied intelligence, [13][14][15][16][17] bio-inspired manipulators, 18,19 soft modular robots, 20,21 and soft deployable robots. 22 However, in most of these case studies, tensegrity structures are characterized by a predefined and fixed stiffness.…”

Section: Introductionmentioning

confidence: 99%

Phase Changing Materials-Based Variable-Stiffness Tensegrity Structures

et al. 2020

View full text Add to dashboard Cite

Soft robots leverage deformable bodies to achieve different types of locomotion, improve transportability, and safely navigate cluttered environments. In this context, variable-stiffness structures provide soft robots with additional properties, such as the ability to increase forces transmitted to the environment, to lock into different body configurations, and to reduce the number of actuators required for morphological change. Tensegrity structures have been recently proposed as a biologically inspired design principle for soft robots. However, the few examples of tensegrity structures with variable stiffness displayed relatively small stiffness change (i.e., by a factor of 3) or resorted to multiple and bulky actuators. In this article, we describe a novel design approach to variable-stiffness tensegrity structures (VSTSs) that relies on the use of variable-stiffness cables (VSCs). As an example, we describe the design and implementation of a three-strut tensegrity structure with VSCs made of low melting point alloys. The resulting VSTS displays unprecedented stiffness changes by a factor of 28 in compression and 13 in bending. We show the capabilities of the proposed VSTS in three validation scenarios with different tensegrity architectures: (1) a beam with tunable load-bearing capability, (2) a structure that can self-deploy and lock its shape in both deployed and undeployed states, and (3) a joint with underactuated shape deformations.

show abstract

“…The redundant links impart robust and fault tolerance, the strategic prestressed cable-link combination provides them with compliance and shape morphing ability (packing-unpacking) (Skelton et al, 2001 ). These qualities have attracted considerable attention from roboticists to design tensegrity mobile robots for space and exploration applications (Paul et al, 2005 , 2006 ; Shibata et al, 2009 ; Böhm et al, 2012 , 2016 ; Khazanov et al, 2013 ; Bruce et al, 2014 ; Kim et al, 2014 ; Sabelhaus et al, 2015 ; Lin et al, 2016 ; Zappetti et al, 2017 ; Mintchev et al, 2018 ; Vespignani et al, 2018 ).…”

Section: Introductionmentioning

confidence: 99%

“…Currently, the design methodologies utilize jigs, multiple sets of hands and precise fabrication to achieve symmetric cable tension and link compression (Böhm et al, 2016 ; Chen et al, 2017a ; Kim et al, 2017 ; Cera and Agogino, 2018 ). Recently, planar-to-three-dimensional solutions have been explored using flexible lattice networks which are excellent for fabricating known morphologies which may not be altered post-assembly (Chen et al, 2017a ; Zappetti et al, 2017 ). The compressive elements (links) are made of rigid material, including wood (Kim et al, 2014 ), plastics (Böhm et al, 2016 ), and metals (Paul et al, 2006 ; Sabelhaus et al, 2015 ; Chen et al, 2017a ; Kim et al, 2017 ).…”

Section: Introductionmentioning

confidence: 99%

“…The compressive elements (links) are made of rigid material, including wood (Kim et al, 2014 ), plastics (Böhm et al, 2016 ), and metals (Paul et al, 2006 ; Sabelhaus et al, 2015 ; Chen et al, 2017a ; Kim et al, 2017 ). The tensile and compliant elements are fabricated using cables, metal extension springs (Böhm et al, 2012 ; Khazanov et al, 2013 ; Bruce et al, 2014 ; Lin et al, 2016 ; Kim et al, 2017 ; Cera and Agogino, 2018 ) and elastic cables comprised of various plastics (Paul et al, 2006 ; Chen et al, 2017a ; Zappetti et al, 2017 ; Mintchev et al, 2018 ). Springs may span the full cable length (Böhm et al, 2012 ; Khazanov et al, 2013 ), or pair in series with other cable materials (Bruce et al, 2014 ; Kim et al, 2017 ; Cera and Agogino, 2018 ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compact Shape Morphing Tensegrity Robots Capable of Locomotion

2019

View full text Add to dashboard Cite

Robustness, compactness, and portability of tensegrity robots make them suitable candidates for locomotion on unknown terrains. Despite these advantages, challenges remain relating to ease of fabrication, shape morphing (packing-unpacking), and locomotion capabilities. The paper introduces a design methodology for fabricating tensegrity robots of varying morphologies with modular components. The design methodology utilizes perforated links, coplanar (2D) alignment of components and individual cable tensioning to achieve a 3D tensegrity structure. These techniques are utilized to fabricate prism (three-link) tensegrity structures, followed by tensegrity robots in icosahedron (six-link), and shpericon (curved two-link) formation. The methodology is used to explore different robot morphologies that attempt to minimize structural complexity (number of elements) while facilitating smooth locomotion (impact between robot and surface). Locomotion strategies for such robots involve altering the position of center-of-mass (referred to as internal mass shifting) to induce “tip-over.” As an example, a sphericon formation comprising of two orthogonally placed circular arcs with conincident center illustrates smooth locomotion along a line (one degree of freedom). The design of curved links of tensegrity mechanisms facilitates continuous change of the point of contact (along the curve) that results from the tip-over. This contrasts to the sudden and piece-wise continuous change for the case of robots with traditional straight links which generate impulse reaction forces during locomotion. The two resulting robots—the Icosahedron and the Sphericon Tensegrity Robots—display shape morphing (packing-unpacking) capabilities and achieve locomotion through internal mass-shifting. The presented static equilibrium analysis of sphericon with mass is the first step in the direction of dynamic locomotion control of these curved link robots.

show abstract

Bio-inspired Tensegrity Soft Modular Robots

Cited by 46 publications

References 22 publications

Design and Manufacturing of Tendon-Driven Soft Foam Robots

Design and Manufacturing of Tendon-Driven Soft Foam Robots

Phase Changing Materials-Based Variable-Stiffness Tensegrity Structures

Compact Shape Morphing Tensegrity Robots Capable of Locomotion

Contact Info

Product

Resources

About