posted on 2021-07-22, 12:03authored byYingzhi Liu, Ansu Sun, Sreepathy Sridhar, Zhenghong Li, Zhuofan Qin, Ji Liu, Xue Chen, Haibao Lu, Ben Zhong Tang, Ben Bin Xu
Autonomous
shape transformation is key in developing high-performance
soft robotics technology; the search for pronounced actuation mechanisms
is an ongoing mission. Here, we present the programmable shape morphing
of a three-dimensional (3D) curved gel structure by harnessing multimode
mechanical instabilities during free swelling. First of all, the coupling
of buckling and creasing occurs at the dedicated region of the gel
structure, which is attributed to the edge and surface instabilities
resulted from structure-defined spatial nonuniformity of swelling.
The subsequent developments of post-buckling morphologies and crease
patterns collaboratively drive the structural transformation of the
gel part from the “open” state to the “closed”
state, thus realizing the function of gripping. By utilizing the multi-stimuli-responsive
nature of the hydrogel, we recover the swollen gel structure to its
initial state, enabling reproducible and cyclic shape evolution. The
described soft gel structure capable of shape transformation brings
a variety of advantages, such as easy to fabricate, large strain transformation,
efficient actuation, and high strength-to-weight ratio, and is anticipated
to provide guidance for future applications in soft robotics, flexible
electronics, offshore engineering, and healthcare products.