Electrical stimulation has recently received attention as noninvasive treatment in skin wound healing with its outstanding biological property for clinical setting. However, the complexity of equipment for applying appropriate electrical stimulation remains an ongoing challenge. Here, we proposed a strategy for skin scar inhibition by providing electrical stimulation via a multilayer stacked electret (MS-electret), which can generate direct current (DC) electric field (EF) without any power supply equipment. In addition, the MS-electret can easily control the intensity of EFs by simply stacking electret layers and maintain stable EF with the surface potential of 3400 V over 5 days owing to the injected charges on the electret surface. We confirmed inhibition of type 1 collagen and α-SMA expression of human dermal fibroblasts (hDFs) by 90% and 44% in vitro, indicating that the transition of hDFs to myofibroblasts was restricted by applying stable electrical stimulation. We further revealed a 20% significant decrease in the ratio of myofibroblasts caused by the MS-electret in vivo. These findings present that the MS-electret is an outstanding candidate for effective skin scar inhibition with a battery-free, physiological electrical microenvironment, and noninvasive treatment that allows it to prevent external infection.
The emulation of human multisensory functions to construct artificial perception systems is an intriguing challenge for developing humanoid robotics and cross-modal human–machine interfaces. Inspired by human multisensory signal generation and neuroplasticity-based signal processing, here, an artificial perceptual neuro array with visual-tactile sensing, processing, learning, and memory is demonstrated. The neuromorphic bimodal perception array compactly combines an artificial photoelectric synapse network and an integrated mechanoluminescent layer, endowing individual and synergistic plastic modulation of optical and mechanical information, including short-term memory, long-term memory, paired pulse facilitation, and “learning-experience” behavior. Sequential or superimposed visual and tactile stimuli inputs can efficiently simulate the associative learning process of “Pavlov's dog”. The fusion of visual and tactile modulation enables enhanced memory of the stimulation image during the learning process. A machine-learning algorithm is coupled with an artificial neural network for pattern recognition, achieving a recognition accuracy of 70% for bimodal training, which is higher than that obtained by unimodal training. In addition, the artificial perceptual neuron has a low energy consumption of ~20 pJ. With its mechanical compliance and simple architecture, the neuromorphic bimodal perception array has promising applications in large-scale cross-modal interactions and high-throughput intelligent perceptions.
Pathogenic and corrosive bacteria pose a significant risk to human health or economic well-being. The specific, sensitive, and on-site detection of these bacteria is thus of paramount significance but remains challenging. Taking inspiration from immunoassays with primary and secondary antibodies, we describe here a rational design of microbial sensor (MS) under a dual-specificity recognition strategy using Pseudomonas aeruginosa (P. aeruginosa) as the detection model. In the MS, engineered aptamers are served as the primary recognition element, while polydopamine-N-acetyl-D-galactosamine (PDA-Gal NAc) nanoparticles are employed as the secondary recognition element, which will also generate and amplify changes in the output voltage signal. To achieve self-powering capability, the MS is constructed based on a triboelectric nanogenerator (TENG) with the specific aptamers immobilized on the TENG electrode surface. The as-prepared MS-TENG system exhibits good stability in output performance under external forces, and high specificity toward P. aeruginosa, with no cross-reactivity observed. A linear relationship (R2 = 0.995) between the output voltage and P. aeruginosa concentration is established, with a limit of detection estimated at around 8.7 × 103 CFU mL−1. The utilization of PDA-Gal NAc nanoparticles is found to play an important role in enhancing the specific and reliability of detection, and the underlying mechanisms are further clarified by computational simulations. In addition, the MS-TENG integrates a wireless communication module, enabling real-time monitoring of bacterial concentration on mobile devices. This work introduces a pioneering approach to designing self-powered smart microbial sensors with high specificity, using a double recognition strategy applicable to various bacteria beyond P. aeruginosa.
Protonic solid oxide electrolysis cells (P-SOECs) operating at intermediate temperatures, which have low costs, low environmental impact, and high theoretical electrolysis efficiency, are considered promising next-generation energy conversion devices for green hydrogen production. However, the developments and applications of P-SOECs are restricted by numerous material- and interface-related issues, including carrier mismatch between the anode and electrolyte, current leakage in the electrolyte, poor interfacial contact, and chemical stability. Over the past few decades, considerable attempts have been made to address these issues by improving the properties of P-SOECs. This review comprehensively explores the recent advances in the mechanisms governing steam electrolysis in P-SOECs, optimization strategies, specially designed components, electrochemical performance, and durability. In particular, given that the lack of suitable anode materials has significantly impeded P-SOEC development, the relationships between the transferred carriers and the cell performance, reaction models, and surface decoration approaches are meticulously probed. Finally, the challenges hindering P-SOEC development are discussed and recommendations for future research directions, including theoretical calculations and simulations, structural modification approaches, and large-scale single-cell fabrication, are proposed to stimulate research on P-SOECs and thereby realize efficient electricity-to-hydrogen conversion.
The recent progress on the liquid crystalline (LC) dispersion of two-dimensional (2D) transition metal carbides (MXenes) has propelled this unique nanomaterial into a realm of high-performance architectures, such as films and fibers. Additionally, compared to architectures made from typical non-LC dispersions, those derived from LC MXene possess tunable ion transport routes and enhanced conductivity and physical properties, demonstrating great potential for a wide range of applications, such as electronic displays, smart glasses, and thermal camouflage devices. This review provides an overview of the progress achieved in the production and processing of LC MXenes, including critical discussions on satisfying the required conditions for LC formation. It also highlights how acquiring LC MXenes has broadened the current solution-based manufacturing paradigm of MXene-based architectures, resulting in unprecedented performances in their conventional applications (e.g., energy storage and strain sensing) and in their emerging uses (e.g., tribology). Opportunities for innovation and foreseen challenges are also discussed, offering future research directions on how to further benefit from the exciting potential of LC MXenes with the aim of promoting their widespread use in designing and manufacturing advanced materials and applications.
Magnesium-ion batteries (MIBs) have promising applications because of their high theoretical capacity and the natural abundance of magnesium Mg. However, the kinetic performance and cyclic stability of cathode materials are limited by the strong interactions between Mg ions and the crystal lattice. Here, we demonstrate the unique Mg2+-ion storage mechanism of a hierarchical accordion-like vanadium oxide/carbon heterointerface (V2O3@C), where the V2O3 crystalline structure is reconstructed into a MgV3O7∙H2O phase through an anodic hydration reaction upon first cycle, for the improved kinetic and cyclic performances. As verified by in situ/ex situ spectroscopic and electrochemical analyses, the fast charge transfer kinetics of the V2O3@C cathode were due to the crystal-reconstruction and chemically coupled heterointerface. The V2O3@C demonstrated an ultrahigh rate capacity of 130.4 mAh g−1 at 50 000 mA g−1 and 1000 cycles, achieving a Coulombic efficiency of 99.6%. The high capacity of 381.0 mA h g−1 can be attributed to the reversible Mg2+-ion intercalation mechanism observed in the MgV3O7∙H2O phase using a 0.3 M Mg(TFSI)2/ACN(H2O) electrolyte. Additionally, within the voltage range of 2.25 V versus Mg/Mg2+, the V2O3@C exhibited a capacity of 245.1 mAh g−1 when evaluated with magnesium metal in a 0.3 M Mg(TFSI)2 + 0.25 M MgCl2/DME electrolyte. These research findings have important implications for understanding the relationship between the Mg-ion storage mechanism and reconstructed crystal phase of vanadium oxides as well as the heterointerface reconstruction for the rational design of MIB cathode materials.
The anomalous Hall effect (AHE) that associated with the Berry curvature of occupied electronic states in momentum-space is one of the intriguing aspects in condensed matter physics, and provides an alternative for potential applications in topological electronics. Previous experiments reported the tunable Berry curvature and the resulting magnetization switching process in the AHE based on strain engineering or chemical doping. However, the AHE modulation by these strategies are usually irreversible, making it difficult to realize switchable control of the AHE and the resultant spintronic applications. Here, we demonstrated the switchable control of the Berry-curvature-related AHE by electrical gating in itinerant ferromagnetic Cr7Te8 with excellent ambient stability. The gate-tunable sign reversal of the AHE can be attributed to the redistribution of the Berry curvature in the band structure of Cr7Te8 due to the intercalation-induced change in the Fermi level. Our work facilitates the applications of magnetic switchable devices based on gate-tunable Berry curvature.
Organic solar cells (OSCs) have emerged as a promising solution for sustainable energy production, offering advantages such as a low carbon footprint, short energy payback period, and compatibility with eco-solvents. However, the use of hazardous solvents continues to dominate the best-performing OSCs, mainly because of the challenges of controlling phase separation and domain crystallinity in eco-solvents. In this study, we combined the solvent vapor treatment of CS2 and thermal annealing to precisely control the phase separation and domain crystallinity in PM6:M-Cl and PM6:O-Cl systems processed with the eco-solvent o-xylene. This method resulted in a maximum power conversion efficiency (PCE) of 18.4%, which is among the highest values reported for sustainable binary OSCs. Furthermore, the fabrication techniques were transferred from spin coating in a nitrogen environment to blade printing in ambient air, retaining a PCE of 16.0%, showing its potential for high-throughput and scalable production. In addition, a comparative analysis of OSCs processed with hazardous and green solvents was conducted to reveal the differences in phase aggregation. This work not only underscores the significance of sustainability in OSCs but also lays the groundwork for unlocking the full potential of open-air-printable sustainable OSCs for commercialization.