Reprogrammable soft actuation and shape-shifting via tensile jamming

Abstract

The emerging generation of robots composed of soft materials strives to match biological motor adaptation skills via shape-shifting. Soft robots often harness volumetric expansion directed by strain limiters to deform in complex ways. Traditionally, strain limiters have been inert materials embedded within a system to prescribe a single deformation. Under changing task demands, a fixed deformation mode limits adaptability. Recent technologies for on-demand reprogrammable deformation of soft bodies, including thermally activated variable stiffness materials and jamming systems, presently suffer from long actuation times or introduce unwanted bending stiffness. We present fibers that switch tensile stiffness via jamming of segmented elastic fibrils. When jammed, tensile stiffness increases more than 20× in less than 0.1 s, but bending stiffness increases only 2×. When adhered to an inflating body, jamming fibers locally limit surface tensile strains, unlocking myriad programmable deformations. The proposed jamming technology is scalable, enabling adaptive behaviors in emerging robotic materials that interact with unstructured environments.

Stress‐Induced Shape‐Shifting Materials Possessing Autonomous Self‐Healing and Scratch‐Resistant Ability

“…Materials exhibiting recyclability and shape shifting ability offer a sustainable platform to develop various complex shapes with unprecedented simplicity and is considered as a plausible alternative to the 3D and 4D printing technology [1,2] . Such materials hold promise in several emerging areas ranging from robotics, [3,4] coatings, additive manufacturing, [5] artificial muscles, [6] soft actuators, biomedical, [7] fluidics and complex architectures [8,9] . Various approaches have been utilized in recent literature to induce shape morphing abilities into materials [10,11] .…”

Locally controllable magnetic soft actuators with reprogrammable contraction-derived motions

“…Reprogrammability refers to the ability to alter the functions repeatedly according to different needs, which has become one of the hallmarks for new-generation advanced actuators to enable versatility and adaptability ( 6 , 17 , 18 ). Reprogrammable soft actuators are especially suitable for working in continually changing conditions and performing multitask by one entirety ( 6 ).…”

“…Actually, bending can also be realized through uneven shrinkage. With contraction-based motions, magnetic actuation modes can be largely expanded, and more sought-after motions can be evolved ( 18 , 22 ). The other problem regarding local and sequential magnetic control (i.e., controlling the movement of the targeted local part, while other parts remain unchanged unless activated) comes from the intrinsic limitation of the magnetic field.…”

Undulatory Swimming Performance Explored With a Biorobotic Fish and Measured by Soft Sensors and Particle Image Velocimetry

“…The study of these fish locomotion habits culminated in the creation of a number of soft robotics capable of moving in liquids (Struebig et al, 2020;Nguyen and Ho, 2021): Robotic fish mimicking the motion of tuna (Barrett, 1996), even exceeding their hunting speeds (Zhu et al, 2019), robots replicating the rapid "C-start" maneuver seen in carangiform fish (Marchese et al, 2014), or robotic platforms powered acoustically and capable of swimming in three dimensions (Katzschmann et al, 2018(Katzschmann et al, , 2016. Additionally, lateral body movements and reflexbase jumping skills have been transferred to robots (Fan et al, 2005;Wright et al, 2019;Kim J. et al, 2020;Zhao et al, 2020;Yang et al, 2021). The mechanisms by which fish use their soft structures, the interaction between active and passive stiffness control, as well as the internal dynamics, are all under-explored and hold significant potential for bio-mimetic technology transfer .…”