Bioinspired dual-morphing stretchable origami

Abstract

Nature demonstrates adaptive and extreme shape morphing via unique patterns of movement. Many of them have been explained by monolithic shape-changing mechanisms, such as chemical swelling, skin stretching, origami/kirigami morphing, or geometric eversion, that were successfully mimicked in artificial analogs. However, there still remains an unexplored regime of natural morphing that cannot be reproduced in artificial systems by a “single-mode” morphing mechanism. One example is the “dual-mode” morphing of Eurypharynx pelecanoides (commonly known as the pelican eel), which first unfolds and then inflates its mouth to maximize the probability of engulfing the prey. Here, we introduce pelican eel–inspired dual-morphing architectures that embody quasi-sequential behaviors of origami unfolding and skin stretching in response to fluid pressure. In the proposed system, fluid paths were enclosed and guided by a set of entirely stretchable origami units that imitate the morphing principle of the pelican eel’s stretchable and foldable frames. This geometric and elastomeric design of fluid networks, in which fluid pressure acts in the direction that the whole body deploys first, resulted in a quasi-sequential dual-morphing response. To verify the effectiveness of our design rule, we built an artificial creature mimicking a pelican eel and reproduced biomimetic dual-morphing behavior. By compositing the basic dual-morphing unit cells into conventional origami frames, we demonstrated architectures of soft machines that exhibit deployment-combined adaptive gripping, crawling, and large range of underwater motion. This design principle may provide guidance for designing bioinspired, adaptive, and extreme shape-morphing systems.

Kirigami‐Inspired Inflatables with Programmable Shapes

“…Very popular among children in the form of party balloons, inflatables have also been employed in science and engineering to enable the design of a variety of systems, including temporary shelters [1,2,3], airbags [4,5], soft robots [6,7,8,9,10,11] and shapemorphing structures [12,13,14,15]. To design shape changing inflatable structures, two main strategies have been pursued.…”

“…Further, since we must reach ε tot φ = 1.094 in the 7th row upon inflation, we obtain w e = 2.53 mm from Eq. (8). Guided by these calculations, we use FE simulations to predict how the response of a kirigami unit cell is affected by the removal of a kirigami strip of width w e = 2.53 mm.…”

Status of and trends in soft pneumatic robotics

“…Color online) Elastic folding/wrinkling actuators driven by positive pressure. (a) Fluidic origami structure[99]; (b) pneumatic actuator based on elastic Miura origami structure[100]; (c) soft actuator based on dual-morphing Miura origami structure[101].…”

Origami transformation in machines at multiple scales

“…(2) It has been used on transformable machines [37,38] such as in medical robots due to its deployable nature [ 39,40,41] (Fig. 1.3(c-e)), and also combined with soft robotics to achieve dual-morphing structures [42] ( Fig. 1.3(f)).…”

“…If done, we can adjust material properties during transformation to achieve easier transformations as well as increase the functionality of the structure. Another interesting topic is to combine origami research with soft robotics, which have been introduced in Kim et al [42] to create dual-morphing mechanisms.…”