Chromophores that exhibit aggregation‐induced emission (i.e., aggregation‐induced emission luminogens [AIEgens]) emit intense fluorescence in their aggregated states, but show negligible emission as discrete molecular species in solution due to the changes in restriction and freedom of intramolecular motions. As solvent‐swollen quasi‐solids with both a compact phase and a free space, gels enable manipulation of intramolecular motions. Thus, AIE‐active gels have attracted significant interest owing to their various distinctive properties and promising application potential. Herein, a comprehensive overview of AIE‐active gels is provided. The fabrication strategies employed are detailed, and the applications of AIEgens are summarized. In addition, the gel functions arising from the AIE moieties are revealed, along with their structure–property relationships. Furthermore, the applications of AIE‐active gels in diverse areas are illustrated. Finally, ongoing challenges and potential means to address them are discussed, along with future perspectives on AIE‐active gels, with the overall aim of inspiring research on novel materials and ideas.

The cation antisite is the most recognizable intrinsic defect type in nickel‐rich layered and olivine‐type cathode materials for lithium‐ion batteries, and important for electrochemical/thermal performance. While how to generate the favorable antisite has not been put forward, herein, by combining first‐principles calculation with neutron powder diffraction (NPD) study, a defect inducing the favorable antisite mechanism is proposed to improve cathode stability, that is, halogen substitution facilitates the neighboring Li and Ni atoms to exchange their sites, forming a more stable local octahedron of halide (LOSH). According to the mechanism, it is demonstrated by NPD that F‐doping not only induces the antisite formation in layered LiNi 0.85 Co 0.075 Mn 0.075 O 2 (LNCM), but also increases the antisite concentration linearly. F substitution (1%) induces 5.7% antisite, and it displays an excellent capacity retention of 94% at 1 C for 200 cycles under 25 °C, outstanding high temperature cyclability (153.4 mAh·g –1 at 1 C for 120 cycles under 55 °C). The onset decomposition temperature increases by 48 °C. The ultrahigh cycling/thermal stability is attributed to the stronger LOSH, and it keeps the structural integrity after long cycling and develops an electrostatic repulsion force between oxygen layers to increase the lattice parameter c , which benefits Li‐ion migration.

Living systems, including human beings, animals, and plants, display the power to self-heal spontaneously after being damaged. The self-healing is usually selective, which means that the healing efficiency is related to the spatial distribution of dynamic interfacial interactions of the two rupturing surfaces. Current artificial systems use noncovalent interactions or dynamic covalent bonds to prepare self-healing materials. However, they can only show nonselective self-healing due to their homogeneous internal structures. Herein, we report the construction of a composite hydrogel Gel-C consisting of three different self-healing hydrogels (Gel-Y, Gel-G, and Gel-O) through the use of classic bilayer hydrogel technology. When the composite hydrogel was cut into two pieces, the relative orientation of the parts was rotated through different angles to study the differences in self-healing. Owing to the heterogeneous internal structure of the composite hydrogel and the recognition specificity of each included hydrogel, the interfacial dynamic interactions distribution of the two rupturing surfaces is diverse. The results of tensile tests demonstrated that these rotated samples exhibited different self-healing efficiencies. This system realized the transformation of artificial materials from nonselective self-healing to selective selfhealing, providing inspiration for the development of novel biological materials and engineering materials.

Microscopic control of macroscopic phenomena is one of the core subjects in materials science. Particularly, the spatio‐temporal control of material behaviors through a non‐contact way is of fundamental importance but is difficult to accomplish. Herein, a strategy to realize remote spatio‐temporal control of luminescence behaviors is reported. A multi‐arm salicylaldehyde benzoylhydrazone‐based aggregation‐induced emission luminogen (AIEgen)/metal‐ion system, of which the fluorescence can be gated by the UV irradiation with time dependency, is developed. By changing the metal‐ion species, the fluorescence emission and the intensity can also be tuned. The mechanism of the UV‐mediated fluorescence change is investigated, and it is revealed that a phototriggered aggregation‐induced emission (PTAIE) process contributes to the behaviors. The AIEgen is further covalently integrated into a polymeric network and the formed gel/metal‐ion system can achieve laser‐mediated mask‐free writing enabled by the PTAIE process. Moreover, by further taking advantage of the time‐dependent self‐healing property of hydrazone‐based dynamic covalent bond, transformable 4D soft patterns are generated. The findings and the strategy increase the ways to manipulate molecules on the supramolecule or aggregate level. They also show opportunities for the development of controllable smart materials and expand the scope of the materials in advanced optoelectronic applications.

natural skin, which has significant applications in wearable health care devices, intelligent robotics, implantable medical devices, and human-machine interfaces. [4][5][6][7] Different sensing mechanisms including capacitance, [8] piezoresistivity, [9] piezoelectricity, [10] and triboelectricity, [11] have mainly been used to convert external stimuli into electronic impulses for quantitative and spatial detection. Among them, piezoresistive effect has been widely used in the design and fabrication of tactile sensor due to the advantages of large detection, simple signal processing, and strong anti-interference capability. [12][13][14][15][16][17][18][19] Novel materials and structure have been applied in the design of high performance tactile sensors in recent researches. A hybrid 3D structure based on ultralight and superelastic MXene/ reduced graphene oxide aerogel is adopted to design a piezoresistive sensor by Yihua Gao etc., which exhibits the sensitivity of 22.56 kPa −1 , and limit detection (10 Pa). [20] Kai Pan's group reported a piezoresisitive pressure sensor based on aPANF/GA aerogel with a 3D interconnected hierarchical microstructure to monitor the real time movement of wrist pulse and main joints of human body. [21] Tactile sensors with high performance containing high sensitivity, wide detection range, fast response, flexibility, and mechanical durability are most concerned in the recent progress of e-skin. [22] Additionally, special functional properties such as self-healing, self-powered, biodegradable, biocompatible, and Resistive pressure sensors have been widely studied for application in flexible wearable devices due to their outstanding pressure-sensitive characteristics. In addition to the outstanding electrical performance, environmental friendliness, breathability, and wearable comfortability also deserve more attention. Here, a biodegradable, breathable multilayer pressure sensor based piezoresistive effect is presented. This pressure sensor is designed with all biodegradable materials, which show excellent biodegradability and breathability with a three-dimensional porous hierarchical structure. Moreover, due to the multilayer structure, the contact area of the pressure sensitive layers is greatly increased and the loading pressure can be distributed to each layer, so the pressure sensor shows excellent pressuresensitive characteristics over a wide pressure sensing range (0.03-11.60 kPa) with a high sensitivity (6.33 kPa −1 ). Furthermore, the sensor is used as a human health monitoring equipment to monitor the human physiological signals and main joint movements, as well as be developed to detect different levels of pressure and further integrated into arrays for pressure imaging and a flexible musical keyboard. Considering the simple manufacturing process, the low cost, and the excellent performance, leaf vein-based pressure sensors provide a good concept for environmentally friendly wearable devices.

Li3BO3 co-melts with Li6.4La3Zr1.4Ta0.6O12 to produce an amorphous boracic phase that consolidate the grain boundary, ultimately attaining garnet electrolyte with high Li+ conductivity.

Fluorescence-guided phototherapy, including photodynamic and photothermal therapy, is considered an emerging noninvasive strategy for cancer treatments. Organic molecules are promising theranostic agents because of their facile construction, simple modification, and good biocompatibility. Organic systems that integrated multifunctionalities in a single component and achieved high efficiency in both imaging and therapies are rarely reported as the inherently competitive energy relaxation pathways are hard to modulate, and fluorescence quenching occurs upon molecular aggregation. Herein, a versatile theranostic platform with near-infrared emission, high fluorescence quantum yield, robust reactive oxygen species production, and excellent photothermal conversion efficiency was developed based on an aggregation-induced emission luminogen, namely, TPA-TBT. In vivo studies revealed that the TPA-TBT nanoaggregates exhibit outstanding photodynamic and photothermal therapy efficacy to ablate tumors inoculated in a mouse model. This work offers a design strategy to develop one-for-all cancer theranostic agents by modulating and utilizing the relaxation energy of excitons in full.

Specific bioconjugation for native primary amines is highly valuable for both chemistry and biomedical research. Despite all the efforts, scientists lack a proper strategy to achieve high selectivity for primary amines, not to mention the requirement of fast response in real applications. Herein, we report a chromone-based aggregation-induced emission (AIE) fluorogen called CMVMN as a self-reporting bioconjugation reagent for selective primary amine identification, and its applications for monitoring bioprocesses of amination and protein labeling. CMVMN is AIE-active and capable of solid-state sensing. Thus, its electrospun films are manufactured for visualization of amine diffusion and leakage process. CMVMN also shows good biocompatibility and potential mitochondria-staining ability, which provides new insight for organelle-staining probe design. Combined with its facile synthesis and good reversibility, CMVMN would not only show wide potential applications in biology, but also offer new possibilities for molecular engineering.