Fully 3D-Printed Hydrogel Actuator for Jellyfish Soft Robots

Abstract

Recently, interest to develop soft robots that mimic flora and fauna in the natural environment has been growing in order to meet the demand for shortage in labor, working in hazardous environments, disaster management, health care and oceanography. Actuators that are made from soft materials, such as elastomers and hydrogels, are integral components of soft robots. Although, 3D printing is a versatile technique to fabricate prototypes, it is a well-known fact that 3D printing for soft materials is challenging. In this work, we present the fabrication and characterization of 3D-printed hydrogel soft actuator that mimics a jellyfish. The developed actuators consist of three parts; (1) Connector: which is the joint part between the main body of actuator and the inlet tube for air pressure, (2) Box: which is balloon-like inflation part and; (3) Base: which is connected to the Box. The results indicate that the normalized contraction ratio of the 3D-printed actuator is close value to that of moon jellyfish and is applicable to a jellyfish-mimic robot. Furthermore, it is observed that, the relationship between applied air pressure and injected volume is linear without balloon defects.

Fluid-driven hydrogel actuators with an origami structure

“…Compared with the existing fluid-driven hydrogel actuators ( Yuk et al., 2017 ; Shintake et al., 2017 ; Zhang et al., 2018 ; Mishra et al., 2020 ; Takishima et al., 2021 ; Mishra et al., 2021 ; Hardman et al., 2022 ), whose practical applications would be restricted by their lack of actuation diversity, the fluid-driven hydrogel actuators with origami structures herein achieve more diverse actuation movements through different origami designs. With the modular design thinking, combinations of multiple actuator modules can realize actuation combinations and reprogramming of actuation modes.…”

“…Compared with molding methods ( Shintake et al., 2017 ; Yuk et al., 2017 ; Zhang et al., 2018 ; Hardman et al., 2022 ), this facile fabrication strategy is capable of fabricating 3D thin-walled hollow hydrogels with complex shapes and structures. Unlike 3D printing methods for hydrogels (including direct-ink-write ( Cheng et al., 2019 ; Heiden et al., 2022 ) and stereolithography ( Mishra et al., 2020 ; Mishra et al., 2021 ; Takishima et al., 2021 )), its equipment is readily available and low cost. The thickness and mechanical properties of the formed thin-walled hydrogels can be regulated by adjusting the forming time and the processes of ion diffusion and hydrogel crosslinking, including the concentration of the precursor solution, the concentration of initiators, properties of template materials, shape of templates, and so on.…”

“…However, on the one hand, as a result of the lack of structural diversity, most existing fluid-driven hydrogel actuators ( Yuk et al., 2017 ; Shintake et al., 2017 ; Zhang et al., 2018 ; Mishra et al., 2020 ; Mishra et al., 2021 ; Takishima et al., 2021 ; Hardman et al., 2022 ) can only perform a simple bending actuation, which would limit their further applications in practice. Baumgartner et al.…”

Peptide‐Reinforced Amphiphilic Polymer Conetworks

“…[ 16 ] For example, hydrogels require a strength of ≈1000 kPa for continuous load bearing scenarios in, e.g., tissue engineering. [ 14b ] Other applications where tough hydrogels and, potentially, APCNs are interesting include soft robotics (muscle‐like actuators, [ 17 ] electrically assisted actuators, [ 18 ] jelly fish soft robots, [ 19 ] ) wearable electronics, [ 20 ] tissue engineering, [ 21 ] drug delivery, [ 2a ] elastomeric materials, [ 22 ] and water evaporation membranes. [ 8 ]…”

Non-Assembly 3D-Printed Walking Mechanism Utilising a Hexapod Gait

“…Models of creatures, such as elephants and caterpillars, with moveable joints and soft elements have also been produced using the method [5,6,7], as well as reproductions of human spines [8]. Various types of joints and actuators have also been produced with 3D printing, using a range of materials, including metal universal joints [9], artificial rubber based Series Elastic Elements, or SEE's [10], flexible pneumatic and hydraulic actuators [11,12,13], sprung joints [14], Shape memory materials [15] and full complement bearing joints [16]. Origami style robots designed to function as medical gripping arms have been produced with Non-Assembly techniques [17], and work has been performed to explore 3D printing shapes around required electro-mechanical components, such as a propeller motor in a model plane [18].…”