Bioinspired Microhinged Actuators for Active Mechanism-Based Metamaterials.

Mechanism-based metamaterials, comprising rigid elements interconnected by flexible hinges, possess the potential to develop intelligent micromachines with programmable motility and morphology. However, the absence of efficient microactuators has constrained the ability to achieve multimodal locomotion and active shape-morphing behaviors at the micro and nanoscale. In this study, inspiration from the flight mechanisms of tiny insects is drawn to develop a biomimetic microhinged actuator by integrating compliant mechanisms with soft hydrogel muscle.

Intelligent Shape-Morphing Micromachines.

Intelligent machines are capable of switching shape configurations to adapt to changes in dynamic environments and thus have offered the potentials in many applications such as precision medicine, lab on a chip, and bioengineering. Even though the developments of smart materials and advanced micro/nanomanufacturing are flouring, how to achieve intelligent shape-morphing machines at micro/nanoscales is still significantly challenging due to the lack of design methods and strategies especially for small-scale shape transformations. This review is aimed at summarizing the principles and methods for the construction of intelligent shape-morphing micromachines by introducing the dimensions, modes, realization methods, and applications of shape-morphing micromachines.

Magnetic cilia carpets with programmable metachronal waves.

Metachronal waves commonly exist in natural cilia carpets. These emergent phenomena, which originate from phase differences between neighbouring self-beating cilia, are essential for biological transport processes including locomotion, liquid pumping, feeding, and cell delivery. However, studies of such complex active systems are limited, particularly from the experimental side.

Superrepellency of underwater hierarchical structures on leaf.

Biomimetic superhydrophobic surfaces display many excellent underwater functionalities, which attribute to the slippery air mattress trapped in the structures on the surface. However, the air mattress is easy to collapse due to various disturbances, leading to the fully wetted Wenzel state, while the water filling the microstructures is difficult to be repelled to completely recover the air mattress even on superhydrophobic surfaces like lotus leaves. Beyond superhydrophobicity, here we find that the floating fern, , has the superrepellent capability to efficiently replace the water in the microstructures with air and robustly recover the continuous air mattress.

Publisher Correction: Nanomagnetic encoding of shape-morphing micromachines.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Nanomagnetic encoding of shape-morphing micromachines.

Shape-morphing systems, which can perform complex tasks through morphological transformations, are of great interest for future applications in minimally invasive medicine, soft robotics, active metamaterials and smart surfaces. With current fabrication methods, shape-morphing configurations have been embedded into structural design by, for example, spatial distribution of heterogeneous materials, which cannot be altered once fabricated. The systems are therefore restricted to a single type of transformation that is predetermined by their geometry.

Matryoshka-Inspired Micro-Origami Capsules to Enhance Loading, Encapsulation, and Transport of Drugs.

Stimuli-responsive hydrogels are promising candidates for use in the targeted delivery of drugs using microrobotics. These devices enable the delivery and sustained release of quantities of drugs several times greater than their dry weight and are responsive to external stimuli. However, existing systems have two major drawbacks: (1) severe drug leakage before reaching the targeted areas within the body and (2) impeded locomotion through liquids due to the inherent hydrophilicity of hydrogels.