Mechanical Janus Structures by Soft–Hard Material Integration

Abstract

Engineering Janus structures that possess anisotropic features in functions have attracted growing attention for a wide range of applications in sensors, catalysis, and biomedicine, and are yet usually designed at the nanoscale with distinct physical or chemical functionalities in their opposite sides. Inspired by the seamless integration of soft and hard materials in biological structures, here a mechanical Janus structure composed of soft and hard materials with a dramatic difference in mechanical properties at an additively manufacturable macroscale is presented. In the combination of extensive experimental, theoretical, and computational studies, the design principle of soft–hard materials integrated mechanical Janus structures is established and their unique rotation mechanism is addressed. The systematic studies of assembling the Janus structure units into superstructures with well‐ordered organizations by programming the local rotations are further shown, providing a direct route of designing superstructures by leveraging mechanical Janus structures with unique soft–hard material integration. Applications are conducted to demonstrate the features and functionalities of assembled superstructures with local ordered organizations in regulating and filtering acoustic wave propagations, thereby providing exemplification applications of mechanical Janus design in functional structures and devices.

Soft‐Hard Janus Nanoparticles Triggered Hierarchical Conductors with Large Stretchability, High Sensitivity, and Superior Mechanical Properties

“…Due to the excellent deformability of the conductive network to hinder crack propagation, its local reconstruction by self-adaptive deformation could create the new conductive pathways. Consequently, the hierarchical conductor, which can also be called the Janus film due to its distinct components, microstructure, and functionalities on its two sides according to the broad definition of the term "Janus", [51,52] exhibits both exceptional mechanical properties and conductivity at large strain. In addition, the in situ Scheme 1.…”

Biomimetic thermoresponsive superstructures by colloidal soft-and-hard co-assembly

“…At macroscale, the integration of soft and hard materials is relatively easy to implement. Various devices with combined compositions in proper structures have been manufactured to perform a range of mechanical functions, including loading, gripping, and moving (6,(9)(10)(11)(12)(13)(14). By contrast, the miniaturization of similar structures and functions, as an effort to make microactuators, is much more challenging (15,16).…”