Kirigami‐Design‐Enabled Hydrogel Multimorphs with Application as a Multistate Switch. Issue 22 (21st April 2020)

• Record Type: Journal Article
• Authors: Hao, Xing Peng; Xu, Zhao; Li, Chen Yu; Hong, Wei; Zheng, Qiang; Wu, Zi Liang
• Is Part Of: Advanced materials. Volume 32:Issue 22(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-21
• Subjects: hydrogels -- kirigami structures -- morphing configurations -- multitier -- programmed deformation; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202000781
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Morphing materials have promising applications in soft robots, intelligent devices, and so forth. Among the various design strategies, kirigami structures are recognized as a powerful tool to obtain sophisticated 3D configurations and unprecedented properties from planar designs on common materials. Here, some kirigami designs are demonstrated for programmable, multistable 3D configurations from composite hydrogel sheets. Via photolithographic polymerization, perforated composite hydrogel sheets are fabricated, in which soft and active hydrogel strips are patterned in stiff and passive hydrogel frames. When immersed in water, the gel strips buckle out of plane due to swelling mismatch. In the kirigami structures, the geometric continuity is disrupted by the introduction of cutouts, and thus the degrees of deformation freedom increases remarkably. Multiple configurations are obtained in a single composite hydrogel by controlling the buckling direction of each strip. Multitier configurations are also obtained by using a hierarchically designed kirigami structure. A multicontact switch of an electric circuit is designed by harnessing the multitier gel configurations. Furthermore, a rotation mode is realized by introducing chirality in the kirigami design. The versatile design of the kirigami structure for programmable deformations should be applicable for other intelligent materials toward promising applications in biomedical devices and flexible electronics. Abstract : Multistable morphing configurations are obtained in one composite hydrogel with kirigami design by controlling the buckling direction of high‐swelling gel strips constrained by a stiff frame. In the kirigami structure, the introduction of cutouts destroys the geometric continuity, increasing the deformation freedom of the discrete strips. A multistate switch is designed by harnessing the hydrogel multimorphs to control a set of light‐emitting diodes.