Hydrogels with Differentiated Hydrogen-Bonding Networks for Bioinspired Stress Response.

Stress response, an intricate and autonomously coordinated reaction in living organisms, holds a reversible, multi-path, and multi-state nature. However, existing stimuli-responsive materials often exhibit single-step and monotonous reactions due to the limited integration of structural components. Inspired by the cooperative interplay of extensor and flexor cells within Mimosa's pulvini, we present a hydrogel with differentiated hydrogen-bonding (H-bonding) networks designed to enable the biological stress response.

Piezoionic Elastomers by Phase and Interface Engineering for High-Performance Energy-Harvesting Ionotronics.

Piezoionic materials play a pivotal role in energy-harvesting ionotronics. However, a persistent challenge lies in balancing the structural requirements for voltage generation, current conduction, and mechanical adaptability. The conventional approach of employing crystalline heterostructures for stress concentration and localized charge separation, while effective for voltage generation, often compromises the stretchability and long-range charge transport found in homogeneous quasisolid states.

Mechanically Adaptative and Environmentally Stable Ionogels for Energy Harvest.

Converting building and environment heat into electricity is a promising strategy for energy harvest to tackle global energy and environmental problems. The processing challenges, mechanical brittleness, and low environmental tolerance of typical thermoelectric materials, however, prevent them from realizing their full potential when employed in outdoor building systems. Herein, a general concept based on synergistic ionic associations to significantly improve the mechanical properties and harsh environment stability for high-performance ionic-type thermoelectric (i-TE) gels is explored.

Bio-inspired ionic skins for smart medicine.

Ionic skins are developed to mimic the mechanical properties and functions of natural skins. They have demonstrated substantial advantages to serve as the crucial interface to bridge the gap between humans and machines. The first-generation ionic skin is a stretchable capacitor comprising hydrogels as the ionic conductors and elastomers as the dielectrics, and realizes pressure and strain sensing through the measurement of the capacitance.

Hierarchically Anisotropic Networks to Decouple Mechanical and Ionic Properties for High-Performance Quasi-Solid Thermocells.

The rapid growth of wearable systems demands sustainable, mechanically adaptable, and eco-friendly energy-harvesting devices. Quasi-solid ionic thermocells have demonstrated the capability of continuously converting low-grade heat into electricity to power wearable electronics. However, a trade-off between ion conductivity and mechanical properties is one of the most challenging obstacles for developing high-performance quasi-solid thermocells.

Hierarchical Network-Augmented Hydroglasses for Broadband Light Management.

Light management is essential for military stealth, optical information communication, and energy-efficient buildings. However, current light management materials face challenges of limited optical modulation range and poor mechanical properties. Herein, we report a locally confined polymerization (LCP) approach to develop hierarchical network-augmented hydroglasses (HNAH) based on poly(methacrylic acid) for broadband light management as well as mechanical enhancement.

Capturing functional two-dimensional nanosheets from sandwich-structure vermiculite for cancer theranostics.

Clay-based nanomaterials, especially 2:1 aluminosilicates such as vermiculite, biotite, and illite, have demonstrated great potential in various fields. However, their characteristic sandwiched structures and the lack of effective methods to exfoliate two-dimensional (2D) functional core layers (FCLs) greatly limit their future applications. Herein, we present a universal wet-chemical exfoliation method based on alkali etching that can intelligently "capture" the ultrathin and biocompatible FCLs (MgO and FeO) sandwiched between two identical tetrahedral layers (SiO and AlO) from vermiculite.

Dynamic Liquid Gating Artificially Spinning System for Self-Evolving Topographies and Microstructures.

Developments in spinning systems have triggered revolutions ranging from bioengineering tissue scaffolds to emerging smart wearable fabrics, but the structures of the spinning fibers are usually limited by intrinsic channel configurations and the "dead" nozzle's geometry. In contrast, natural living systems, such as a spider spinning apparatus, use a "live" gate to coordinate microstructures via shearing and expanding at both axial and radial directions. Herein, for the first time, we introduce a dynamic liquid gating effect in artificial systems to mimic the spinning in biological organisms.

A highly transparent and ultra-stretchable conductor with stable conductivity during large deformation.

Intrinsically stretchable conductors have undergone rapid development in the past few years and a variety of strategies have been established to improve their electro-mechanical properties. However, ranging from electronically to ionically conductive materials, they are usually vulnerable either to large deformation or at high/low temperatures, mainly due to the fact that conductive domains are generally incompatible with neighboring elastic networks. This is a problem that is usually overlooked and remains challenging to address.

Zwitterionic Skins with a Wide Scope of Customizable Functionalities.

With growing interest in the fields of wearable devices, it is crucial yet rather challenging to develop skinlike soft conductive materials with customizable functionalities and human tissue-compatible mechanical properties. Previously reported electronic skins struggle to meet the demands for transparence, mechanical adaptability, and stable conductivity during deformation. The recent rise of ionic skins with inorganic salts or ionic liquids doping provides the intrinsic stretchability, however, dilemmas remain for their limited functionalities such as a monotonous appearance and a narrow scope of mechanical and sensory properties.

A supramolecular biomimetic skin combining a wide spectrum of mechanical properties and multiple sensory capabilities.

Biomimetic skin-like materials, capable of adapting shapes to variable environments and sensing external stimuli, are of great significance in a wide range of applications, including artificial intelligence, soft robotics, and smart wearable devices. However, such highly sophisticated intelligence has been mainly found in natural creatures while rarely realized in artificial materials. Herein, we fabricate a type of biomimetic iontronics to imitate natural skins using supramolecular polyelectrolyte hydrogels.

A Bioinspired Mineral Hydrogel as a Self-Healable, Mechanically Adaptable Ionic Skin for Highly Sensitive Pressure Sensing.

In the past two decades, artificial skin-like materials have received increasing research interests for their broad applications in artificial intelligence, wearable devices, and soft robotics. However, profound challenges remain in terms of imitating human skin because of its unique combination of mechanical and sensory properties. In this work, a bioinspired mineral hydrogel is developed to fabricate a novel type of mechanically adaptable ionic skin sensor.

MoS-based dual-responsive flexible anisotropic actuators.

A facile approach has been developed to prepare well-designed MoS-based flexible anisotropic actuators with tunable thermo- and photo-responses, in which MoS nanosheets act as the photothermal transduction agents and enable remote and precise control of the actuator locomotion. Taking advantage of the dual-responsive behaviors, programmable locomotion, reversible deformation, good mechanical properties and biocompatibility, the MoS-based flexible anisotropic actuators are very promising in soft robotics for future intelligent applications.

Hydrophilic MoSe2 Nanosheets as Effective Photothermal Therapy Agents and Their Application in Smart Devices.

A facile poly(vinylpyrrolidone) (PVP)-assisted exfoliation method is utilized to simultaneously exfoliate and noncovalently modify MoSe2 nanosheets. The resultant hydrophilic nanosheets are shown to be promising candidates for biocompatible photothermal therapy (PTT) agents, and they could also be encapsulated into a hydrogel matrix for some intelligent devices. This work not only provides novel insights into exfoliation and modification of transition metal dichalcogenide (TMD) nanosheets but also might spark more research into engineering multifunctional TMD-related nanocomposites, which is in favor of further exploiting the attractive properties of these emerging layered two-dimensional (2D) nanomaterials.

Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for "Mineral Plastics".

Given increasing environmental issues due to the large usage of non-biodegradable plastics based on petroleum, new plastic materials, which are economic, environmentally friendly, and recyclable are in high demand. One feasible strategy is the bio-inspired synthesis of mineral-based hybrid materials. Herein we report a facile route for an amorphous CaCO3 (ACC)-based hydrogel consisting of very small ACC nanoparticles physically cross-linked by poly(acrylic acid).

Simultaneous Exfoliation and Functionalization of MoSe2 Nanosheets to Prepare "Smart" Nanocomposite Hydrogels with Tunable Dual Stimuli-Responsive Behavior.

A facile polymer-assisted method achieves simultaneous exfoliation and noncovalent functionalization of MoSe2 nanosheets. The nanosheet dispersion can further assemble into a novel "smart" nanocomposite hydrogel, whose dual-responsive (photo- and thermoresponsive) behavior is reversible and can be controllably tailored by varying the distribution of hydrophilic and hydrophobic groups in the polymer.

Facile synthesis of N-rich carbon quantum dots by spontaneous polymerization and incision of solvents as efficient bioimaging probes and advanced electrocatalysts for oxygen reduction reaction.

In this study, uniform nitrogen-doped carbon quantum dots (N-CDs) were synthesized through a one-step solvothermal process of cyclic and nitrogen-rich solvents, such as N-methyl-2-pyrrolidone (NMP) and dimethyl-imidazolidinone (DMEU), under mild conditions. The products exhibited strong light blue fluorescence, good cell permeability and low cytotoxicity. Moreover, after a facile post-thermal treatment, it developed a lotus seedpod surface-like structure of seed-like N-CDs decorating on the surface of carbon layers with a high proportion of quaternary nitrogen moieties that exhibited excellent electrocatalytic activity and long-term durability towards the oxygen reduction reaction (ORR).

Ultra-thin and porous MoSe2 nanosheets: facile preparation and enhanced electrocatalytic activity towards the hydrogen evolution reaction.

In this study, ultra-thin and porous molybdenum selenide (MoSe2) nanosheets were prepared through a modified liquid exfoliation method as efficient electrocatalysts for the hydrogen evolution reaction (HER). This novel structure enables the exposure of more catalytically active sites and moreover maintains effective electron transport, resulting in a small peak potential of ∼75 mV as well as long-term durability. In addition, due to the facile and economical preparation method as well as its eco-friendly synthetic conditions, this study provides a high-performance HER catalyst with promising commercial application prospects.

Facile preparation and multifunctional applications of boron nitride quantum dots.

Boron nitride quantum dots are obtained by a facile sonication-solvothermal technique. They are proven to be promising fluorescent bioimaging probes for bioimaging with remarkably low cytotoxicity and easily integrated into high-performance proton exchange membranes. This work will probably trigger research interest in BN and its new applications in a variety of fields.