Tissue monolayers are active living matter whose three-dimensional (3D) architecture and mechanical remodeling regulate tissue function, yet fast and continuous topographic monitoring remains difficult. Here, we present FLuorescence EXclusion microscopy fOr Monolayers (FLEXOM), a microfluidic platform that combines multilayer micropillar arrays with negative-staining optics to convert wide-field images into self-calibrated 3D height maps. Geometry-anchored reference cavities maintain in-frame calibration standards even in fully confluent monolayer fields, enabling continuous 3D profiling from isolated cells to confluent sheets with sub-second temporal resolution (~250 ms), sub-micrometer axial precision (~0.37 μm), and multi-day biocompatibility and operational stability (>96 h). FLEXOM reveals two distinct anisotropic signatures in tissue monolayers. First, monolayers of different cell types show distinct vertical thickness profiles despite comparable lateral footprints. Only two vertical descriptors, mean height and height variability, distinguished cell types more accurately than nine 2D lateral descriptors, including area, circularity, and convexity (95% vs. 76%). Second, under acute osmotic shock, confluent monolayers exhibit geometrically anisotropic and temporally decoupled vertical-lateral remodeling: height changes dominate the overall volume response and precede lateral remodeling. Surprisingly, cyclic isotonic-hypotonic pulses every 3 min confine remodeling entirely to the vertical axis. Overall, our work provides a high-resolution 3D profiling tool and a framework for axis-resolved analysis of topographic responses in active living matter.

Convection-enhanced delivery enables local administration of therapeutic agents to brain tissues by overcoming the challenges posed by the blood-brain barrier. However, its efficacy is limited by the lack of control over the delivery pathway. To address this, we propose infusion and iontophoresis for directional delivery of compounds in the brain (IIDD). This IIDD strategy involves the insertion of a cannula for drug infusion, along with two plateshaped electrodes serving as the cathode and anode and positioned at predetermined sites in the brain. Iontophoresis generates an electrical path for controlled, directional transport of the injected compound. We tested it with gadobutrol, a clinically approved, negatively charged gadolinium-based contrast agent. We observed that increasing the duration of application of current (fixed current of 10 mu A) facilitated significantly better migration of gadobutrol toward the anode than simple diffusion by convection-enhanced delivery alone. Simulation data derived from three-dimensional finite element modeling were consistent with the experimental findings. This further confirmed the feasibility of infusion and iontophoresis for directional delivery of compounds in the brain.

Ethynyl parylene, fabricated via CVD, modulates dielectric properties through azide/alkyne click reactions. Surface modification increases the dielectric constant, leading to drain current variation in TFTs, enabling its use as a sensor device.

Whitlockite (WH), a magnesium-enriched bone mineral, offers significant potential for bone regeneration due to its high bioresorbability and osteogenic properties. Despite these advantages, its application has been hindered by challenges in synthesizing WH directly on implant surfaces. To address this, a laser-assisted strategy is developed for the in situ formation of WH-containing coatings on bone implants. To overcome the thermodynamic and kinetic barriers of WH synthesis, a magnesium calcium phosphate (MCP) intermediate is employed, a kinetically accessible and magnesium-rich phase, as a precursor to WH. The MCP intermediate is readily produced via laser-induced hydrothermal processing from a magnesium-enriched solution. Subsequent localized laser irradiation enabled partial transformation of the MCP into WH. Multiscale analyses confirmed successful WH formation, showing rhombohedral morphology and distinct chemical features. In vivo testing in a rat femoral defect model showed that WH-integrated implants significantly enhanced bone-implant integration and early-stage vascularization, attributed to the sustained release of osteogenic calcium and magnesium ions. This laser-assisted method can offer a scalable and effective strategy for implant surface modification in regenerative medicine.

The magnesium nitrate (Mg(NO3)2) additive triggers the formation of lithiophilic Li–Mg alloy and conductive Li3N on Li metal surface, leading to long lifespan of Li metal anode over 3000 h under high capacity loading.

To advance high-energy-density Li-S batteries, it is crucial to develop strategies that enhance the energy efficiency, power capability, and cycle stability of both lithium metal anodes (LMAs) and sulfur cathodes (SCs). This study introduces an ultra-thin (∼60 nm) lithium telluride (t-Li2Te) layer on a conventional polypropylene (PP) separator, designed to improve the Coulombic efficiency (CE) and cycling stability of LMAs and SCs. The t-Li2Te layer features a nanoporous structure of aggregated Li2Te nanoparticles, with nanopores filled by solid-electrolyte interface (SEI) materials during initial lithium deposition. This t-Li2Te-SEI nanohybrid layer significantly enhanced CE for LMA, reaching maximum capacity within four cycles with only 25 % total capacity loss, contrasting with a 210 % capacity loss over ten cycles in the bare PP-based anode without t-Li2Te. In high cut-off capacity tests (4 mA h cm-2), the t-Li2Te-based system achieved stable cycling over 350 cycles, extending cycle life tenfold compared to the bare PP-based anode. For SC applications, the t-Li2Te-SEI nanohybrid layer attained an initial CE of 98.3 %, notably higher than that (93.1 %) of the reference system. After 100 cycles, the t-Li2Te-based SC system retained 85 % capacity, showing a 20 % improvement over systems without the nanohybrid layer.

Intrinsically-stretchable organic solar cells (IS-OSCs) are an emerging class of wearable power sources owing to their ability to stretch in multiple directions. However, their current stretchability remains insufficient to meet...

In this study, the first noncontact and non-destructive methodology is developed for monitoring and imaging the operation and performance of thin-film field-effect transistors (TFTs) using second-harmonic generation (SHG) imaging. By analyzing the SHG signal intensity, which is directly related to the electric field at the interface between the semiconductor channel and gate insulator, critical electrical parameters such as the threshold voltage (VTH) and flat-band voltage (VFB) are successfully determined. These findings demonstrate a strong correlation between SHG signals and VTH and VFB in InGaZnO TFTs under various process conditions. Notably, the method achieves an unprecedented resolution of ΔVFB below 100 mV in assessing electrical properties through SHG measurements, surpassing conventional spectroscopy techniques. Furthermore, a system is developed to monitor and image the TFT array operation and performance, enabling us to distinguish between pass and fail devices and measure the VTH distribution based on the SHG intensity. This approach facilitates early failure detection and supports efficient curing during manufacturing, thereby marking significant advancements in TFT technology and quality control processes.

Ongoing research is actively being undertaken to identify alternatives to Co for high-capacity Ni-rich NCM cathode materials, driven by concerns related to cost and ethics. In this context, Na was proposed as a suitable replacement for Co. In addition, a process utilizing a pH-dependent polymer was introduced for the controlled doping of the material to ensure uniformity, and Co-free Ni-rich cathode materials with a form where Na is intensively doped in the surface region. The resulting material exhibits superior rate capabilities (20C, 121 mAh/ g) and high-voltage, fast-rate cycle performance (100 cycles, 2.5-4.5 V (vs. Li/Li+), 2C) compared to the pristine LiNi0.8Mn0.2O2. Notably, surface-intensive doping with Na during high-voltage, fast-rate cycles suppressed the formation of oxygen vacancies in Ni-rich materials. This study introduces a novel approach to improving the performance of Co-free Ni-rich materials.

The development of flexible and stretchable devices is crucial for realizing future electronics. In particular, for dielectric layer, conventional inorganic materials are limited by their brittle nature, while organic materials suffer from a low dielectric constant. Here, a novel intrinsically photopatternable high-k Parylene-based thin film (Parylene-OH) is fabricated via a chemical vapor deposition process based on the Gorham method, which provides pin-hole free, conformal polymeric film on any type of surface. Parylene-OH can be photo-patterned by UV crosslinking without further lithography processes and dielectric constant of Parylene-OH increases from 6.05 to 7.53 after crosslinking, without degrading other parameters, making it comparable to conventional high-k dielectric, Al2O3. Flexible InGaZnO (IGZO) thin-film transistors (TFTs) with patterned dielectric layers can withstand higher strain owing to the localized pattern of each unit. A CMOS inverter integrated with n-type IGZO and p-type Te TFTs is successfully fabricated. Parylene-OH can be used in the future of state-of-the-art flexible electronic devices. The demand for flexible and high-performance devices is increasing with the development of flexible electronics. This study proposes a novel CVD-processable polymer dielectric, Parylene-OH, as a crucial alternative to brittle inorganic dielectrics. Parylene-OH offers a high-quality smooth film with high dielectric constant and photopatternability, positioning it as a promising choice for future flexible devices. image

Development of miniaturized thin-film lithium-ion batteries (TF-LIBs) using vacuum deposition techniques is crucial for low-scale applications, but addressing low energy density remains a challenge. In this work, structures analogous to SiOx-based thin-film electrodes are designed with close resemblance to traditional LIB slurry formulations including active material, conductive agent, and binder. The thin-film is produced using mid-frequency sputtering with a single hybrid target consisting of SiOx nanoparticles, carbon nanotubes, and polytetrafluoroethylene. The thin-film SiOx/PPFC (plasma-polymerized fluorocarbon) involves a combination of SiOx and conductive carbon within the PPFC matrix. This results in enhanced electronic conductivity and superior elasticity and hardness in comparison to a conventional pure SiOx-based thin-film. The electrochemical performance of the half-cell consisting of thin-film SiOx/PPFC demonstrates remarkable cycling stability, with a capacity retention of 74.8% up to the 1000th cycle at 0.5 C. In addition, a full cell using the LiNi0.6Co0.2Mn0.2O2 thin-film as the cathode material exhibits an exceptional initial capacity of ≈120 mAh g-1 at 0.1 C and cycle performance, marked by a capacity retention of 90.8% from the first cycle to the 500th cycle at a 1 C rate. This work will be a stepping stone for the AM/CB/B composite electrodes in TF-LIBs.

In this study, sodium nitrate (NaNO3) dissolves in a carbonate electrolyte for K-metal batteries (KMBs) using a dimethylacetamide (DMA) solvent with a higher Gutmann donor number than that of NO3−. The K-metal anode in 0.02 M NaNO3 electrolyte exhibits enhanced stability due to the modified solid-electrolyte interphase (SEI) layer resulting from the preferential reduction of NaNO3. Reduced NaNO3 forms ionically conductive and mechanically robust compounds in the SEI layer. This compound plays a critical role in altering the morphology of electrodeposited K-metal from dendritic to spherical, reducing the barrier energy of nucleation potential for K-ions. These unique features make K-metal highly resistant to dendrite formation and aggressive electrolyte chemistry. Therefore, the K-metal anode in the proposed electrolyte containing 0.02 M NaNO3 additive ensures excellent cycle life with stable Coulombic efficiency in both symmetrical K/K half cells and full-cells coupled with a Prussian green FeFe(CN)6 cathode.

Neuromorphic computing is a rapidly emerging technology that can overcome the limitations of von Neumann-type architecture-based computing systems, offering the potential for implementing next-generation computing architectures. Here, we propose a p-type three-terminal synaptic device that successfully mimics the function of biological synapses. The proposed tellurium (Te) synaptic transistors incorporating SiO2 or Al2O3 gate dielectric layers modulate the synaptic weight-that is, the channel conductance-essential for realizing synaptic characteristics. Synaptic devices with optimal Al2O3 layers exhibit large hysteresis properties that efficiently induce conductance modulation, demonstrating low power consumption, good linearity, and short-/long-term plasticity. Furthermore, the proposed optimal Te synaptic transistor achieved a high recognition accuracy of 93.8%. These findings suggest that Te-based synaptic devices fabricated utilizing thin-film processes could enhance the efficiency of future neuromorphic computing systems.

Cobalt-free cathode materials, particularly Ni-rich layered oxide cathode materials, are ideal for electric vehicle Li-ion batteries, offering high energy density and cost-effectiveness. However, high Ni content in high-temperature synthesis leads to issues like increased Li/Ni cation mixing and reduced rate capability, mainly due to the absence of Co. Therefore, this study investigated the utilization of a small amount of Co instead of completely removing it to enhance electrochemical performance. A simple pre-calcination process was used to induce Co substitution beneath the Ni-rich layered oxide cathode materials surface. A coating process was also performed for comparison. The Li/Ni cation mixing in the Co-substituted sample during high-temperature calcination was 2.43%, demonstrating a superior value compared to the Co-coating process. Rate capability tests showed superior performance for Co-substituted sample (164.2 mAh g-1) at 2C compared to coated sample (151.0 mAh g-1). Moreover, Co substitution improved not only the cycle stability but also the high-temperature stability at an elevated state of charge.This study focuses on the surface modification of cobalt-free cathode, providing direct insight into the effects of Co substitution and typical Co coating and suggests an optimal process that uses small amounts of Co.

BACKGROUND AND OBJECTIVE:Multichannel transcranial electrical stimulation (tES) is widely used to achieve improved stimulation focality. In the multichannel tES, the injection current pattern is generally determined through an optimization process with a finite element (FE) head model extracted from individual magnetic resonance images (MRIs). Although using an individual head model ensures the best outcome, acquiring MRIs of individual subjects in many practical applications is often difficult. Alternatively, a standard head model can be used to determine the optimal injection current pattern to stimulate a specific target; however, this may result in a relatively inaccurate delivery of stimulation current owing to the difference in individual anatomical structures. To address this issue, we propose a new approach for determining the injection current pattern using multiple head models, which can improve the stimulation focality compared to that achieved with a single standard head model.METHODS:Twenty FE head models were used to optimize the injection current patterns to stimulate three cortical regions that are widely considered targets for tES. The individual injection current patterns were then averaged to obtain each target's mean injection current pattern. The stimulation focality for each target was then calculated by applying different current patterns (the mean current, individual current, and current from a standard model).RESULTS:Our results showed that the stimulation focality obtained using the mean injection current pattern was significantly higher than that obtained using the injection current pattern from a standard head model. Additionally, our results demonstrated that a minimum of 13 head models are required to determine mean current pattern, allowing for a higher stimulation focality than when using the current from a standard head model.CONCLUSIONS:Hence, using multiple head models can provide a viable solution for improving the stimulation efficacy of multichannel tES when individual MRIs are not available.

The concept of a lithiophilic electrode proves inadequate in describing carbon-based electrode materials due to their substantial mismatch in surface energy with lithium metal. However, their notable capacity for lithium chemisorption can increase active lithium concentration required for nucleation and growth, thereby enhancing the electrochemical performance of lithium metal anodes (LMAs). In this study, we elucidate the effects of the supersaturated electrode which has high active lithium capacity around equilibrium lithium potential on LMAs through an in-depth electrochemical comparison using two distinct carbon electrode platforms with differing carbon structures but similar two-dimensional morphologies. In the supersaturated electrode, both the dynamics and thermodynamic states involved in lithium nucleation and growth mechanisms are significantly improved, particularly under continuous current supply conditions. Furthermore, the chemical structures of the solid-electrolyte-interface layers (SEIs) are greatly influenced by the elevated surface lithium concentration environment, resulting in the formation of more conductive lithium-rich SEI layers. The improved dynamics and thermodynamics of surface lithium, coupled with the formation of enhanced SEI layers, contribute to higher power capabilities, enhanced Coulombic efficiencies, and improved cycling performances of LMAs. These results provide new insight into understanding the enhancements in heterogeneous lithium nucleation and growth kinetics on the supersaturated electrode.

Abundant and economical sodium (Na) metal batteries promise superior energy densities compared to lithium-ion batteries; however, they face commercialization challenges owing to problematic interfacial reactions leading to dendrite formation during cycling. This paper reports the ultra-long and rapid operation of Na metal batteries enabled by the introduction of a vinylpyrrolidone (VP)-based multifunctional interface stabilizer in the electrolyte. The VP electrolyte additive provides benefits such as surface flattening, durable solid electrolyte interphase layer formation, preservation of fresh Na, and acceleration of horizontal crystal growth along the (110) plane. Symmetric Na-Na cells with the stabilizer exhibit notably stable operation for over 5 000 cycles at a high current density of 5 mA cm-2, surpassing previous research. Performance improvement is also demonstrated in a full-cell configuration with an Na3V2(PO4)2O2F cathode. This approach offers a promising solution for achieving performance levels comparable to lithium-ion batteries in Na metal battery technology. Na-metal batteries offer exceptional energy merits comparable to existing Li-ion batteries, yet problematic dendrite formation and unstable surface side reactions on the Na anode must be addressed. The ultra-long and rapid operating performance is achieved in Na-metal batteries by introducing polarizable vinylpyrrolidone molecules dissolved in the electrolyte as a surface-flattening and interface-stabilizing additive. image

High-capacity and high-voltage Li-rich cathode materials are promising candidates for next-generation LIB cathodes due to their high energy density characteristics. However, they face challenges such as electrolyte side reactions at high voltages and slow kinetic properties. To overcome these challenges, this study proposed a one-pot Li2WO4 (LWO) grain boundary coating method. Additionally, a novel synthesis process utilizing zwitterions was introduced to uniformly position heavy tungsten on the surface of a cathode material. Through grain boundary coating, the cathode material was modified not only at the secondary particle level, but also between primary particles by filling grain boundaries with the coating compound. The synthesized LWO grain boundary coated Li-rich cathode exhibited significantly superior rate capability and cycle stability compared to the pristine material. Furthermore, it demonstrated a more stable cycling behavior after high-temperature storage than pristine counterpart. This study presents a primary particle surface modification technique through grain boundary coating and a one-pot synthesis process leveraging zwitterions as a new driving force, providing a new perspective for enhancing the performance of Li-rich cathode materials.

Lithium metal anodes, which are promising candidates for anode materials in Li-ion batteries, are highly regarded for their combination of high energy density and low electrochemical potential, making them a compelling option for next-generation anodes. However, the growth of dendritic Li during the charging and discharging processes, along with the resulting decrease in stability and efficiency, poses a significant obstacle to the commercialization of Li metal anodes. To address the challenges associated with Li metal anodes, we propose the use of hollow carbon incorporating zinc oxide (ZnO) and magnesium oxide (MgO) as anode materials. ZnO has high lithiophilicity, enabling selective reactions with Li ions, and MgO exhibits a low nucleation overpotential. By placing these two substances inside the hollow carbon structure, stable Li growth can occur within the hollow carbon, enabling the formation of a reliable Li metal anode. Furthermore, to simplify and precisely synthesize the proposed structure, polystyrene-b-polyacrylic acid was introduced. Metals such as Zn and Mg can be uniformly attached to the hollow carbon through the carboxylic group of acrylic acid. The synthesized structure exhibited significantly improved Li storage performance compared to that of hollow carbon. It demonstrated superior metrics, achieving a Coulombic efficiency of 99.8% over 350 cycles. The introduction of Zn and Mg with distinct properties effectively enhanced the internal storage performance of Li in hollow carbon.

Batteries using potassium metal (K-metal) anode are considered a new type of low-cost and high-energy storage device. However, the thermodynamic instability of the K-metal anode in organic electrolyte solutions causes uncontrolled dendritic growth and parasitic reactions, leading to rapid capacity loss and low Coulombic efficiency of K-metal batteries. Herein, an advanced electrolyte comprising 1 M potassium bis(fluorosulfonyl)imide (KFSI) + 0.05 M potassium hexafluorophosphate (KPF6) dissolved in dimethoxyethane (DME) is introduced as a simple and effective strategy of regulated solvation chemistry, showing an enhanced interfacial stability of the K-metal anode. Incorporating 0.05 M KPF6 into the 1 M KFSI in DME electrolyte solution decreases the number of solvent molecules surrounding the K ion and simultaneously leads to facile K+ de-solvation. During the electrodeposition process, these unique features can lower the exchange current density between the electrolyte and K-metal anode, thereby improving the uniformity of K electrodeposition, as well as potentially suppressing dendritic growth. Even under a high current density of 4 mA cm(-2), the K-metal anode in 0.05 M KPF6-containing electrolyte ensures high areal capacity and an unprecedented lifespan with stable Coulombic efficiency in both symmetrical half-cells and full-cells employing a sulfurized polyacrylonitrile cathode.