Advanced Materials最新文献

Magnetic interfacial microrobots are increasingly recognized as a promising approach for potential biomedical applications ranging from electronic functionalization to minimally invasive surgery and targeted drug delivery. Nevertheless, existing research faces challenges, including less cooperative interactions, contact-based cargo manipulation, and slow transport velocity. Here, the cooperative magnetic interfacial microrobot couple (CMIMC) is proposed to address the above challenges. The CMIMC can be maneuvered by a single magnet and readily switched between capture and release states. By leveraging cooperative interactions and meticulous engineering of capillary forces through shape design and surface treatment, the CMIMC demonstrates the ability to perform non-contact cargo manipulation. Using the synergy of preferred magnetization directions and magnetic field distribution, along with optimization of the resistance-reducing shape, the CMIMC significantly enhances the cargo transport velocity, reaching 12.2 body length per second. The studies demonstrate various biomedical applications like targeted drug delivery and myomectomy, paving the way for the broad implementation of interfacial microrobots in biomedical fields.

Recently, fervent research interest is sparked to indium selenide (γ-InSe) due to its dazzling optical and electronic properties. The direct bandgap in the near-infrared (NIR) range ensures efficient carrier recombination in InSe, promoting impressive competency for lavish NIR applications. Nevertheless, the photoluminescence (PL) efficiency of InSe is significantly limited by out-of-plane (OP) excitons, adverse to practical devices. Herein, a facile and effective solution is proposed by introducing photonic bound-states-in-the-continuum (BIC) modes to enhance excitons in InSe through strengthened exciton-photon coupling. This cavity is constructed simply by patterning a polymer grating onto the InSe flake without an etching process, achieving an impressive PL enhancement of over 200 times. By adjusting the cavity resonance wavelength, it can selectively amplify the exciton emission or the exciton-exciton scattering process, which is not observable off-cavity at room temperature. Additionally, the second harmonic generation (SHG) process in InSe can also be largely enhanced by over 400 times on the cavity. Notably, the etchless cavity design can be further extended to other nanostructures beyond grating. This research presents a feasible and efficient approach to enhancing the optical performance of OP excitons, paving a prospective avenue for advanced linear and nonlinear photonic devices.

Tribovoltaic nanogenerator (TVNG), which manifests distinct advantages of direct-current output characteristics and remarkable energy utilization efficiency, is an emerging energy technology relying on the coupling of semiconductor and contact electrification. Dynamic semiconductor interface is the key to TVNGs, as its performance and functionality largely depend on the design and optimization of interface. Hence, with the booming development of TVNGs, it is of great significance to timely update the fundamental understanding of its interface design, which is currently lacking. In this review, the frontier advances on interface design for TVNGs are elaborately outlined for the first time. First, the underlying mechanisms of tribovoltaic effect at the interface are elaborated, as well as some governing equations and key interface design concepts. Subsequently, diverse strategies for advanced interface design are highlighted, including modulating interfacial charge dynamics, multi-energy coupling, reducing interface wear loss, and extending flexible/wearable application. At last, some assumptions about the future direction and prospects of advanced interface design in efficient, multifunctional TVNGs are presented.

Owing to the exotic state of quantum matter, topological insulators have emerged as a significant platform for new-generation functional devices. Among these topological insulators, tetradymites have received significant attention because of their van der Waals (vdW) structures and inversion symmetries. Although this inversion symmetry completely blocks exotic quantum phenomena, it should be broken down to facilitate versatile topological functionalities. Recently, a Janus structure is suggested for asymmetric out-of-plane lattice structures, terminating the heterogeneous atoms at two sides of the vdW structure. However, the synthesis of Janus structures has not been achieved commercially because of the imprecise control of the layer-by-layer growth, high-temperature synthesis, and low yield. To overcome these limitations, plasma sulfurization of vdW topological insulators has been presented, enabling stochastic inversion asymmetry. To take practical advantage of the random lattice distortion, physically unclonable functions (PUFs) have been suggested as applications of vdW Janus topological insulators. The sulfur dominance is experimentally demonstrated via X-ray photoelectron spectroscopy, hysteresis variation, cross-sectional transmission electron microscopy, and adhesion energy variation. In conclusion, it is envisioned that the vdW Janus topological insulators can provide an extendable encryption platform for randomized lattice distortion, offering on-demand stochastic inversion asymmetry via a single-step plasma sulfurization.

Altermagnetism, a newly identified class of magnetism blending characteristics of both ferromagnetism and antiferromagnetism, is emerging as a compelling frontier in spintronics. This study reports a groundbreaking discovery of robust, 100% field-free spin-orbit torque (SOT) switching in a RuO₂(101)/[Co/Pt]₂/Ta structure. The experimental results reveal that the spin currents, induced by the in-plane charge current, flow along the [100] axis, with the spin polarization direction aligned parallel to the Néel vector. These z-polarized spins generate an out-of-plane anti-damping torque, enabling deterministic switching of the Co/Pt layer without the necessity of an external magnetic field. The altermagnetic spin splitting effect (ASSE) in RuO₂ promotes the generation of spin currents with pronounced anisotropic behavior, maximized when the charge current flows along the [010] direction. This unique capability yields the highest field-free switching ratio, maintaining stable SOT switching even under a wide range of external magnetic fields, demonstrating exceptional resistance to magnetic interference. Notably, the ASSE-dominated spin current is found to be most effective when the current is aligned with the [010] direction. The study highlights the potential of RuO₂ as a powerful spin current generator, opening new avenues for advancing spin-torque switching technologies and other cutting-edge spintronic devices.

Solid polymer electrolytes (SPEs) are promising for high-energy and high-safety solid-state lithium metal batteries (LMBs). Here, a polycationic solid electrolyte (PCSE) is described that leverages the inherent high thermal/chemical stability of the polycationic domain and the anion trapping (FMAT) effect of another fluorinated microdomain for stable and fast-charging high-voltage LMBs. Specifically, while the polycationic imidazolium backbone ensures high segmental flexibility facilitating the Li⁺ mobility, the fluorinated microdomain effectively traps the bis(trifluoromethanesulfonyl)imide anions by strong dipole interactions, imparting localized solvation and restricted mobility of the anions, as well as improved oxidation stability. As a result, the PCSE exhibits a high ionic conductivity of 1.4 mS cm^-1, a high Li⁺ transference number of 0.50, and a wide electrochemical window of ∼5.5 V at 25 °C. By way of in situ thermal polymerization of the electrolyte within assembled cells, the PCSE enables ultra-stable cycling of Li|LiNi_0.8Co_0.1Mn_0.1O₂ cells with a capacity retention of 98.1% after 500 cycles at 0.2 C at ambient temperatures. The work on the molecular design of PCSEs represents a fundamentally unique perspective for the rational design of SPEs with balanced properties that are historically challenging for high-energy, long-life, ambient-temperature solid-state LMBs.

Ammonia (NH₃) is vital in global production and energy cycles. Electrocatalytic nitrate reduction (e-NO₃RR) offers a promising route for nitrogen (N) conversion and NH₃ synthesis, yet it faces challenges like competing reactions and low catalyst activity. This study proposes a synergistic mechanism incorporating a proton donor to mediate O-end e-NO₃RR, addressing these limitations. A novel method combining ultraviolet radiation reduction, confined synthesis, and microwave treatment was developed to create a model catalyst embedding Cu single atoms on La-based nanoparticles (p-CNCu^sLaⁿ-m). DFT analysis emphasizes the critical role of La-based clusters as proton donors in e-NO₃RR, while in situ characterization reveals an O-end adsorption reduction mechanism. The catalyst achieves a remarkable Faraday efficiency (FE_NH3) of 97.7%, producing 10.6 mol g_metal ^-1 h^-1 of NH₃, surpassing most prior studies. In a flow cell, it demonstrated exceptional stability, with only a 9% decrease in current density after 111 hours and a NH₃ production rate of 1.57 mg_NH3/h/cm^-2. The proton donor mechanism's effectiveness highlights its potential for advancing electrocatalyst design. Beyond NH₃ production, the O-end mechanism opens avenues for exploring molecular-oriented coupling reactions in e-NO₃RR, paving the way for innovative electrochemical synthesis applications.

Contemporary clinical interventions for cartilage injuries focus on symptom management through pharmaceuticals and surgical procedures. Recent research has aimed at developing innovative scaffolds with biochemical elements, yet challenges like inadequate targeted delivery and reduced load-bearing capacity hinder their adoption. Inspired by the spatial gradients of biophysical and biochemical cues in native osteochondral tissues, a silk-based hydrogel that facilitates spontaneous dual-gradient formation, including mechanical gradients and growth factor gradients, for tissue regeneration, is presented. Driven by an electrical field, the hydrogel transitions from stiff to soft along the anode-to-cathode direction, mimicking the anisotropic structure of natural tissues. Simultaneously, incorporated growth factors encapsulated by charged monomers migrate to the cathode region, creating another parallel gradient that enables their sustained release. This design maintains bioactivity and enhances programmable growth factor concentration in the defect environment. In a rabbit model with full-thickness osteochondral defects, the dual-gradient hydrogel demonstrates significant potential for promoting osteochondral regeneration, offering a promising tool for clinical translation.