bluuebunny/crossref_metadata_2025 huggingface dataset:
Solution‐Processed Selective Area Homoepitaxial Growth of Suspended MAPbX3(X = Cl, Br) Perovskite Micro‐Arrays
Authors: Zhang Jinshuai , Li Chun , Liang Yin , Song Jiepeng , Shang Qiuyu , Zhao Liyun , Tian Huifeng , Liu Lei , Zhang Qing
Published: December 2022

Suspended nano/microstructures on semiconductor surfaces that can manage light are attractive for various on‐chip and efficiency‐enhanced optoelectronics. Hybrid halide perovskites have shown considerable potential for optoelectronic and photonic applications. However, the ionic and soft lattices of perovskites are sensitive to polar solvents, photons, and heat, limiting the post‐processing of suspended microstructures. Herein, a solution‐processed selective area homoepitaxial growth (SAEG) method is introduced to create well‐ordered, suspended microstructure arrays on the surface of MAPbX3(X = Br, Cl) single‐crystalline thin films. The suspended micro‐arrays exhibit single crystalline structures and 11.2 fold photoluminescence enhancement compared to the thin‐film substrates. The success of SAEG lies in the making use of perovskite supersaturated HX aqueous solutions that not only repair surface defects induced by lithography but also satisfy homoepitaxial growth kinetics. This study paves a pathway for the fabrication of cost‐effective perovskite surface‐suspended microstructures for efficiency‐enhanced and on‐chip optoelectronic devices.
Highly Symmetrical Six‐Transition Metal Ring Units Promising High Air‐Stability of Layered Oxide Cathodes for Sodium‐Ion Batteries
Authors: Gan Lu , Yuan Xin‐Guang , Han Jia‐Jun , Yang Xinan , Zheng Lituo , Huang Zhigao , Yao Hu‐Rong
Published: December 2022

Layered oxides are the most prevalent cathodes for sodium‐ion batteries (SIBs), but their poor air stability significantly limits their practical application owing to the rapid performance degradation of aged materials and the cost increase for material storage and transportation. Here, an effective strategy of constructing stable transition metal (TM) layers with a highly symmetrical six‐TM ring is suggested to enhance structure stability, thus hindering ambient air corrosion. The density functional theory calculations reveal that the higher symmetry ensures a higher thermodynamic energy for H2O insertion into Na layer. The combined analyses of selected area electron diffraction, transmission electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and chemical titration indicate that the six‐TM ring structure can effectively suppress the series of aging processes including water insertion, the spontaneous loss of lattice sodium, TM valence increment and residual alkali formation. Benefiting from the overall suppression of aging process, the strategy results in an excellent improvement in capacity retention after air exposure from 13.57% to 95.59%, and exhibits a good universality for both P2‐ and O3‐cathodes, which are the two most common structures of Na‐based layered oxides with different aging mechanism. These findings provide new insight to design high‐performance cathodes for SIBs.
Surface‐Engineered Extracellular Vesicles with CDH17 Nanobodies to Efficiently Deliver Imaging Probes and Chemo‐Photothermal Drugs for Gastric Cancer Theragnostic
Authors: Xia Peng , Yuan Haitao , Tian Ming , Zhong Tianyu , Hou Rui , Xu Xiaolong , Ma Jingbo , Wang Huifang , Li Zhifen , Huang Defa , Qu Chengming , Dai Lingyun , Xu Chengchao , Yang Chuanbin , Jiang Haibo , He Yuanqiao , Rückert Felix , Li Zhijie , Yuan Yufeng , Wang Jigang
Published: December 2022

Extracellular vesicles (EVs) are widely used as natural nanoparticles to deliver various cargos for disease diagnosis and therapy. However, unmodified EVs cannot efficiently transport the cargos to desired sites due to non‐specific uptake. Here, a delivery system is designed to display nanobodies against cadherin 17 (CDH17) on the surface of EVs isolated from HEK‐293 cells and loaded with dye Indocyanine green (ICG) and/or anti‐cancer drug dinitroazetidine derivative RRx‐001, a blocker for CD47/ signal regulatory protein alpha (SIRPα) axis. CDH17 is a promising target for gastric cancer (GC) therapy. In this study, ICG loaded in the EVs engineered with CDH17 nanobodies can realize rapid tumor imaging in a CDH17‐positive GC model and can produce significant anti‐tumor photothermal therapeutic (PTT) effect after irradiation. Meanwhile, PTT effect can induce immunogenic cell death and macrophage polarization from M2 to M1 phenotype. The engineered EVs loaded with RRx‐001 can significantly repress GC tumor growth. Finally, dual loading of ICG/RRx‐001 in engineered EVs show maximal anti‐tumor efficacy in both cancer cell and patient‐derived GC models after only single injection. Collectively, CDH17 nanobody‐functionalized EVs loaded with ICG and/or RRx‐001 hold great promise to image and treat GC by combining fluorescent dye‐induced PTT with chemotherapy.
Biopolymer Nanovehicles for Oral Delivery of Natural Anticancer Agents
Authors: Falsafi Seid Reza , Wang Yong , Ashaolu Tolulope Joshua , Sharma Minaxi , Rawal Shruti , Patel Kaushika , Askari Gholamreza , Javanmard Shaghayegh Haghjooy , Rostamabadi Hadis
Published: December 2022

Cancer is the second leading cause of death throughout the world. Nature‐inspired anticancer agents (NAAs) that are a gift of nature to humanity have been extensively utilized in the alleviation/prevention of the disease due to their numerous pharmacological activities. While the oral route is an ideal and common way of drug administration, the application of NAAs through the oral pathway has been extremely limited owing to their inherent features, e.g., poor solubility, gastrointestinal (GI) instability, and low bioavailability. With the development of nano‐driven encapsulation strategies, polymeric vehicles, especially those with natural origins, have demonstrated a potent platform, which can professionally shield versatile NAAs against GI barricades and safely deliver them to the site of action. In this review, the predicament of orally delivering NAAs and the encapsulation strategy solutions based on biopolymer matrices are summarized. Proof‐of‐concept in vitro/in vivo results are also discussed for oral delivery of these agents by various biopolymer vehicles, which can be found so far from the literature. Last but not the least, the challenges and new opportunities in the field are highlighted.
Engineered Lipid Nanoparticles for the Treatment of Pulmonary Fibrosis by Regulating Epithelial‐Mesenchymal Transition in the Lungs
Authors: Jin Hee , Jeong Michaela , Lee Gyeongseok , Kim Minjeong , Yoo Youngjo , Kim Hyun Jin , Cho Jaeho , Lee Yun‐Sil , Lee Hyukjin
Published: December 2022

Pulmonary fibrosis is a chronic and irreversible lung disease with limited therapeutic regimens. Advances in elucidating the pathophysiological mechanism and discovering novel therapeutic interventions are still in urgent need. Here, the engineered lipid nanoparticles (LNPs) are developed for delivering RNA therapeutics to the lungs. Three different types of LNPs (native, cationic, and ligand incorporated) are optimized to facilitate the pulmonary delivery of RNAs. Among them, the mannose incorporated LNPs (Mannose LNPs) outperform the others and show efficient delivery of siRNAs down‐regulating the epithelial‐mesenchymal transition (EMT) associated protein, G2 and S phase‐expressed protein 1 (GTSE1). Treatment with the mannose LNPs confirms a significant decrease in collagen accumulation and EMT‐related proteins in the fibrosis animal models and provides functional recovery from pulmonary fibrosis. This approach demonstrates that engineered LNPs can facilitate the delivery of RNA therapeutics to the lungs and potentially open a new regimen of treatment for pulmonary fibrosis.
Light‐Driven Polymer‐Based All‐Solid‐State Lithium‐Sulfur Battery Operating at Room Temperature
Authors: Wang Peng‐Fei , He Xuewei , Lv Ze‐Chen , Song Hucheng , Song Xiaoying , Yi Ting‐Feng , Xu Ning , He Ping , Zhou Haoshen
Published: December 2022

Poly(ethylene oxide)‐based polymer all‐solid‐state LiS battery is a promising candidate due to its high specific energy, good processability, and low cost. However, the poor room temperature ionic conductivity limits its further development. Here an innovative photothermal battery technology is proposed to realize the normal operation at room temperature. This design places the 3D Cu substrate with Cu/Si core‐shell structures between Li anode and outer encapsulation glass, so that the light can come in and generate heat efficiently by utilizing the carrier nonradiative recombination of Si nano shell, then the heat quickly transfers to the battery system through Cu core. Once simulated sunlight irradiates, the battery achieves a fast reaction kinetics and superior photothermal conversion, thus realizing a lifespan of over 20 cycles with a capacity of 1089.9 mAh g−1 at 0.2 C. Even on the actual sunlight irradiation, a high discharge/charge capacity of 1065.2/1036.5 mAh g−1 is also reached, indicating an excellent reversible electrochemical process. Moreover, the 3D nanostructure can accommodate the fatal volume variation of lithium and reduce the effective current density, thus suppressing the dendrite nucleation and growth. This study will open the avenue to develop a room temperature polymer all‐solid‐state LiS battery using photothermal technology.
3D Direct Laser Writing of Highly Absorptive Photoresist for Miniature Optical Apertures
Authors: Schmid Michael D. , Toulouse Andrea , Thiele Simon , Mangold Simon , Herkommer Alois M. , Giessen Harald
Published: December 2022

The importance of 3D direct laser writing as an enabling technology increased rapidly in recent years. Complex micro‐optics and optical devices with various functionalities are now feasible. Different possibilities to increase the optical performance are demonstrated, for example, multi‐lens objectives, a combination of different photoresists, or diffractive optical elements. It is still challenging to create fitting apertures for these micro optics. In this work, a novel and simple way to create 3D‐printed opaque structures with a highly absorptive photoresist is introduced, which can be used to fabricate microscopic apertures increasing the contrast of 3D‐printed micro optics and enabling new optical designs. Both hybrid printing by combining clear and opaque resists, as well as printing transparent optical elements and their surrounding opaque apertures solely from a single black resist by using different printing thicknesses are demonstrated.
Metallic Zinc Anode Working at 50 and 50 mAh cm−2 with High Depth of Discharge via Electrical Double Layer Reconstruction
Authors: Shi Xin , Wang Jin , Yang Fan , Liu Xiaoqing , Yu Yanxia , Lu Xihong
Published: December 2022

Achieving high‐rate and high‐areal‐capacity Zn anode with high depth of discharge (DOD) offers a bright future for large‐scale aqueous batteries. However, Zn deposition suffers from severe dendrite growth and side reactions, which compromises achievable lifetime. Herein, an electrical double layer (EDL) reconstruction strategy is proposed by employing acetone as electrolyte additive to fully address these issues. Experimental and theoretical simulation results reveal that the adsorption priority of acetone to water on Zn creates a water‐poor inner Helmholtz layer. Meanwhile, the intense hydrogen bonding effect between acetone and water confines the activity of free water and weakens the Zn2+ solvation in the outer Helmholtz layer and diffusion layer. Such ion/molecule rearrangement in EDL suppresses hydrogen evolution, facilitates the desolvation process, and promotes the Zn2+ diffusion kinetics, which guides homogeneous Zn nucleation and uniform growth, even in extreme situations. At both ultrahigh current density of 50 mA cm−2 and areal capacity of 50 mAh cm−2, the addition of 20 v/v% acetone in 2 m ZnSO4 extends the lifespan of Zn//Zn symmetric cells from 12 to 800 h, with a high DOD of 73.5%. The effectiveness of this strategy is further demonstrated in the Zn‐MnO2 full batteries at wide temperature range from −30 to 40 °C.
Scaffold‐Free Tracheal Engineering via a Modular Strategy Based on Cartilage and Epithelium Sheets
Authors: Yang Minglei , Chen Jiafei , Chen Yi , Lin Weikang , Tang Hai , Fan Ziwen , Wang Long , She Yunlang , Jin Feng , Zhang Lei , Sun Weiyan , Chen Chang
Published: December 2022

Tracheal defects lead to devastating problems, and practical clinical substitutes that have complex functional structures and can avoid adverse influences from exogenous bioscaffolds are lacking. Herein, a modular strategy for scaffold‐free tracheal engineering is developed. A cartilage sheet (Cart‐S) prepared by high‐density culture is laminated and reshaped to construct a cartilage tube as the main load‐bearing structure in which the chondrocytes exhibit a stable phenotype and secreted considerable cartilage‐specific matrix, presenting a native‐like grid arrangement. To further build a tracheal epithelial barrier, a temperature‐sensitive technique is used to construct the monolayer epithelium sheet (Epi‐S), in which the airway epithelial cells present integrated tight junctions, good transepithelial electrical resistance, and favorable ciliary differentiation capability. Epi‐S can be integrally transferred to inner wall of cartilage tube, forming a scaffold‐free complex tracheal substitute (SC‐trachea). Interestingly, when Epi‐S is attached to the cartilage surface, epithelium‐specific gene expression is significantly enhanced. SC‐trachea establishes abundant blood supply via heterotopic vascularization and then is pedicle transplanted for tracheal reconstruction, achieving 83.3% survival outcomes in rabbit models. Notably, the scaffold‐free engineered trachea simultaneously satisfies sufficient mechanical properties and barrier function due to its matrix‐rich cartilage structure and well‐differentiated ciliated epithelium, demonstrating great clinical potential for long‐segmental tracheal reconstruction.
Manipulating Charge‐Transfer Kinetics of Lithium‐Rich Layered Oxide Cathodes in Halide All‐Solid‐State Batteries
Authors: Yu Ruizhi , Wang Changhong , Duan Hui , Jiang Ming , Zhang Anbang , Fraser Adam , Zuo Jiaxuan , Wu Yanlong , Sun Yipeng , Zhao Yang , Liang Jianwen , Fu Jiamin , Deng Sixu , Ren Zhimin , Li Guohua , Huang Huan , Li Ruying , Chen Ning , Wang Jiantao , Li Xifei , Singh Chandra Veer , Sun Xueliang
Published: December 2022

Employing lithium‐rich layered oxide (LLO) as the cathode of all‐solid‐state batteries (ASSBs) is highly desired for realizing high energy density. However, the poor kinetics of LLO, caused by its low electronic conductivity and significant oxygen‐redox‐induced structural degradation, has impeded its application in ASSBs. Here, the charge transfer kinetics of LLO is enhanced by constructing high‐efficiency electron transport networks within solid‐state electrodes, which considerably minimizes electron transfer resistance. In addition, an infusion‐plus‐coating strategy is introduced to stabilize the lattice oxygen of LLO, successfully suppressing the interfacial oxidation of solid electrolyte (Li3InCl6) and structural degradation of LLO. As a result, LLO‐based ASSBs exhibit a high discharge capacity of 230.7 mAh g−1 at 0.1 C and ultra‐long cycle stability over 400 cycles. This work provides an in‐depth understanding of the kinetics of LLO in solid‐state electrodes, and affords a practically feasible strategy to obtain high‐energy‐density ASSBs.
Improved Molecular Ordering in a Ternary Blend Enables All‐Polymer Solar Cells over 18% Efficiency
Authors: Cai Yunhao , Xie Cong , Li Qian , Liu Chunhui , Gao Jiaxin , Jee Min Hun , Qiao Jiawei , Li Yun , Song Jiali , Hao Xiaotao , Woo Han Young , Tang Zheng , Zhou Yinhua , Zhang Chunfeng , Huang Hui , Sun Yanming
Published: December 2022

Although all‐polymer solar cells (all‐PSCs) show great commercialization prospects, their power conversion efficiencies (PCEs) still fall behind their small molecule acceptor‐based counterparts. In all‐polymer blends, the optimized morphology and high molecular ordering are difficult to achieve since there is troublesome competition between the crystallinity of the polymer donor and acceptor during the film‐formation process. Therefore, it is challenging to improve the performance of all‐PSCs. Herein, a ternary strategy is adopted to modulate the morphology and the molecular crystallinity of an all‐polymer blend, in which PM6:PY‐82 is selected as the host blend and PY‐DT is employed as a guest component. Benefiting from the favorable miscibility of the two acceptors and the higher regularity of PY‐DT, the ternary matrix features a well‐defined fibrillar morphology and improved molecular ordering. Consequently, the champion PM6:PY‐82:PY‐DT device produces a record‐high PCE of 18.03%, with simultaneously improved open‐circuit voltage, short‐circuit current and fill factor in comparison with the binary devices. High‐performance large‐area (1 cm2) and thick‐film (300 nm) all‐PSCs are also successfully fabricated with PCEs of 16.35% and 15.70%, respectively.Moreover, 16.5 cm2 organic solar module affords an encouraging PCE of 13.84% when using the non‐halogenated solvent , showing the great potential of “Lab‐to‐Fab” transition of all‐PSCs.
Physical Origin of Negative Differential Resistance in V3O5 and Its Application as a Solid‐State Oscillator
Authors: Das Sujan Kumar , Nandi Sanjoy Kumar , Marquez Camilo Verbel , Rúa Armando , Uenuma Mutsunori , Puyoo Etienne , Nath Shimul Kanti , Albertini David , Baboux Nicolas , Lu Teng , Liu Yun , Haeger Tobias , Heiderhoff Ralf , Riedl Thomas , Ratcliff Thomas , Elliman Robert Glen
Published: December 2022

Oxides that exhibit an insulator–metal transition can be used to fabricate energy‐efficient relaxation oscillators for use in hardware‐based neural networks but there are very few oxides with transition temperatures above room temperature. Here the structural, electrical, and thermal properties of V3O5 thin films and their application as the functional oxide in metal/oxide/metal relaxation oscillators are reported. The V3O5 devices show electroforming‐free volatile threshold switching and negative differential resistance (NDR) with stable (<3% variation) cycle‐to‐cycle operation. The physical mechanisms underpinning these characteristics are investigated using a combination of electrical measurements, in situ thermal imaging, and device modeling. This shows that conduction is confined to a narrow filamentary path due to self‐confinement of the current distribution and that the NDR response is initiated at temperatures well below the insulator–metal transition temperature where it is dominated by the temperature‐dependent conductivity of the insulating phase. Finally, the dynamics of individual and coupled V3O5‐based relaxation oscillators is reported, showing that capacitively coupled devices exhibit rich non‐linear dynamics, including frequency and phase synchronization. These results establish V3O5 as a new functional material for volatile threshold switching and advance the development of robust solid‐state neurons for neuromorphic computing.
Stable Cuprous Hydroxide Nanostructures by Organic Ligand Functionalization
Authors: Liu Qiming , Peng Yi , Masood Zaheer , DuBois Davida , Tressel John , Nichols Forrest , Ashby Paul , Mercado Rene , Assafa Tufa , Pan Dingjie , Kuo Han‐Lin , Lu Jennifer Q. , Bridges Frank , Millhauser Glenn , Ge Qingfeng , Chen Shaowei
Published: December 2022

Copper compounds have been extensively investigated for diverse applications. However, studies of cuprous hydroxide (CuOH) have been scarce due to structural metastability. Herein, a facile, wet‐chemistry procedure is reported for the preparation of stable CuOH nanostructures via deliberate functionalization with select organic ligands, such as acetylene and mercapto derivatives. The resulting nanostructures are found to exhibit a nanoribbon morphology consisting of small nanocrystals embedded within a largely amorphous nanosheet‐like scaffold. The acetylene derivatives are found to anchor onto the CuOH forming CuC linkages, whereas CuS interfacial bonds are formed with the mercapto ligands. Effective electronic coupling occurs at the ligand‐core interface in the former, in contrast to mostly non‐conjugated interfacial bonds in the latter, as manifested in spectroscopic measurements and confirmed in theoretical studies based on first principles calculations. Notably, the acetylene‐capped CuOH nanostructures exhibit markedly enhanced photodynamic activity in the inhibition of bacteria growth, as compared to the mercapto‐capped counterparts due to a reduced material bandgap and effective photocatalytic generation of reactive oxygen species. Results from this study demonstrate that deliberate structural engineering with select organic ligands is an effective strategy in the stabilization and functionalization of CuOH nanostructures, a critical first step in exploring their diverse applications.
Recent Advances in 4D Printing of Liquid Crystal Elastomers
Authors: Chen Mei , Gao Ming , Bai Lichun , Zheng Han , Qi H. Jerry , Zhou Kun
Published: December 2022

Liquid crystal elastomers (LCEs) are renowned for their large, reversible, and anisotropic shape change in response to various external stimuli due to their lightly cross‐linked polymer networks with an oriented mesogen direction, thus showing great potential for applications in robotics, bio‐medics, electronics, optics, and energy. To fully take advantage of the anisotropic stimuli‐responsive behaviors of LCEs, it is preferable to achieve a locally controlled mesogen alignment into monodomain orientations. In recent years, the application of 4D printing to LCEs opens new doors for simultaneously programming the mesogen alignment and the 3D geometry, offering more opportunities and higher feasibility for the fabrication of 4D‐printed LCE objects with desirable stimuli‐responsive properties. Here, the state‐of‐the‐art advances in 4D printing of LCEs are reviewed, with emphasis on both the mechanisms and potential applications. First, the fundamental properties of LCEs and the working principles of the representative 4D printing techniques are briefly introduced. Then, the fabrication of LCEs by 4D printing techniques and the advantages over conventional manufacturing methods are demonstrated. Finally, perspectives on the current challenges and potential development trends toward the 4D printing of LCEs are discussed, which may shed light on future research directions in this new field.
Nanostructured, Alkaline Titanate‐Converted, and Heat‐Treated Ti6Al4V Microspheres via Wet‐Chemical Alkaline Modification and their ORR Electrocatalytic Response
Authors: Wadge Matthew D. , Bird Matthew A. , Sankowski Andrzej , Constantin Hannah , Fay Michael W. , Cooper Timothy P. , O'Shea James N. , Khlobystov Andrei N. , Walsh Darren A. , Johnson Lee R. , Felfel Reda M. , Ahmed Ifty , Grant David M.
Published: December 2022

This study describes the chemical conversion and heat treatment of Ti6Al4V microspheres (Ti6_MS), and the resulting effects on their electrocatalytic properties. The wet‐chemical conversion (5.0 m NaOH, 60 °C, 24 h; Sample label: Ti6_TC) converts the top surface of the Ti6_MS powder into an ≈820 nm thick sodium titanate surface. Heat‐treatment (Ti6_TC_HT) at 450 °C increases the stability of the surface, through partial titanate crystallization, while mitigating excess rutile formation. All samples are analyzed chemically (XPS, EDX, Raman, EELS), structurally (XRD and TEM), and morphologically (SEM, TEM), demonstrating the characteristic formation of sodium titanate dendritic structures, with minimal chemical, structural, and morphological differences due to the 450 °C heat‐treatment. The effect of the preparation methodology on oxygen reduction reaction (ORR) electrocatalytic performance is also tested. The introduction of the sodium titanate layer changes the mechanism of the ORR, from a mixed 4 electron/2 electron pathway to a predominantly 2‐electron pathway. By maintaining the microspherical nature of the material while also tuning the surface of the material toward different reaction mechanisms, a design strategy for new electrocatalyst materials is explored.
Low‐Temperature CO2 Reduction using Mg–Ga Liquid Metal Interface
Authors: Ye Linlin , Syed Nitu , Wang Dingqi , Guo Jining , Yang Jianing , Buston Joshua , Singh Ranjeet , Alivand Masood S. , Li Gang Kevin , Zavabeti Ali
Published: December 2022

The need for effective and adaptive technologies for carbon dioxide (CO2) mitigation targeting global net‐zero carbon emissions is critically growing. Hence, innovative technologies for CO2 reduction have attracted worldwide interest from scientific research communities. The use of liquid metals for the conversion of CO2 into carbon or solid carbonaceous products has gained increasing attention in recent years due to their high activity and resistance to coking. Here, a facile approach for the reduction of CO2 to solid carbon using liquid Mg at and near room temperature, and atmospheric pressure is presented. In this process, magnesium (Mg) plays a major role in driving the dissociation of CO2 to its elemental constituents, carbon and oxygen. During the reaction process, Mg ions dissolve in gallium (Ga) liquid metal alloy, diffuse to the gas–liquid interface, and reduce CO2 to carbon while undergoing an oxidation reaction. The electrochemical method ensures a sustainable cyclic process by reducing Mg and Ga ions back to their metallic counterpart. The use of liquid metal alloys for CO2 reduction reactions can enable to achieve CO2 capture and storage at room temperature, setting a new foundation for the future exploration of efficient CO2 mitigation issues.
Interface Co‐Assembly Synthesis of Magnetic Fe3O4@mesoporous Carbon for Efficient Electrochemical Detection of Hg(II) and Pb(II)
Authors: Liu Yuzhi , Wu Shiya , Xiong Wei , Li Hao
Published: December 2022

In recent years, efficient and porous carbon‐layer‐modified magnetic metal oxides demonstrate potentials for the significant improvement of catalytic and adsorption performance. In this study, a novel magnetic coreshell Fe3O4@mesoporous carbon (Fe3O4@MPC) nanochain electrochemical sensor is constructed by using resorcinol‐formaldehyde resin and magnetic Fe3O4 nanospheres as the carbon shell precursor and core, respectively, with a simple emulsion self‐assembly strategy. Microstructural characterizations revealed that the carbon shell exhibited a mesopore distribution of ≈40 nm and the diameter of Fe3O4 nanospheres embedded into carbon is ≈280 nm. The introduction of mesoporous carbon layer increased the electrical conductivity of the active material and maintained the adsorption properties of magnetic Fe3O4. The synergistic effect of the mesoporous carbon layer and Fe3O4 nanochain is beneficial to electrochemically detect heavy metal ions (HMIs). Under optimal conditions, the typical Fe3O4@MPC‐2/GCE exhibited excellent electrochemical sensing for detecting Hg(II) and Pb(II), with limits of detection (LOD) of 7.8 nm and 12.1 nm (S/N = 3), respectively. These good results are attributed to the Fe3O4@MPC nanochain structure and a relatively high specific surface area. This study provides a novel method to prepare magnetic mesoporous carbon nanochain composites for constructing sensitive electrochemical sensors to monitor water quality.
Revealing the Substrate Dependent Ultrafast Phonon Dynamics in Bi2Se3 Thin Films
Authors: Saini Saurabh K. , Tailor Naveen Kumar , Sharma Prince , Tyagi Lavi , Vashistha Nikita , Yadav Rimjhim , Chaudhary Amit Kumar , Satapathi Soumitra , Kumar Mahesh
Published: December 2022

The bulk carrier excitation influences the phonon dynamics, which can alter and modulate the surface charge density of topological insulators such as bismuth selenide (Bi2Se3). This work investigates the charge carrier and phonon dynamics in Bi2Se3 grown on various substrates. The orientation of the substrate, the size of the crystallites, and the misfit of the lattice affect the carrier and phonon dynamics. Bi2Se3 thin films are grown under the same growth conditions on SiO2, Si(111), and SiN. Bi2Se3 overlayers exhibit substrate‐dependent charge carrier relaxation channels and phonon dynamics. It is evident from Raman spectroscopy and ultrafast transient absorption spectroscopy that the heterointerface interactions of all three samples affect the vibration modes of Bi2Se3 and coherent acoustic phonon oscillations in the NIR range. At 13.6, 41.2, and 34.4 GHz, the vibration modes of SiO2, Si(111), and SiN are equivalent. The propagation depth of phonon waves is shown by measuring the speed of sound in Bi2Se3 overlayers on SiO2, Si(111), and SiN. This study demonstrates that the surface and bulk‐bound charge carriers of a topological insulator determine the frequency and velocity of the generated sound.
Dielectric Study of Cost‐Effective, Eco‐Friendly PVA‐Glycerol Matrices with AgNW Electrodes for Transparent Flexible Humidity Sensors
Authors: Gassab Marwa , Papanastasiou Dorina T. , Sylvestre Alain , Bellet Daniel , Dridi Chérif , Basrour Skandar
Published: December 2022

In this work, a deep insight is given into the dielectric properties and the humidity response of flexible polymer matrices, composed of polyvinyl alcohol (PVA) and glycerol (Gly), using silver nanowire networks as transparent electrodes (AgNW TE). These electrodes, known for their high electrical conductivity, optical transparency, and excellent flexibility, are deposited here by open‐air, scalable spray coating technique. Analysis of the dielectric constant ε′ and loss tangent tanδ according to the density of the AgNWs shows that the latter do not cover the entire surface with PVA and induces an interfacial polarization effect. Wide frequency range of impedance spectroscopy (1 Hz to 1 MHz) on both, PVA‐Gly samples with AgNW TE (4 Ω sq−1) networks electrodes and sputtered silver electrodes (Ag bulk el), reveal no significant change in ε′ and tanδ. Finally, the humidity sensing properties of PVA‐Gly exhibit good response between 20% to 90% humidity range and low hysteresis. This is related to the non‐continuous structure of AgNW TE. At 100 Hz, the PVA‐10 wt% Gly presents high sensitivity of 0.08 nF/% RH with an hysteresis value of about 1.5% at 70% RH. These results indicate that AgNW networks show great potential for integration in transparent and flexible humidity sensors.
Multi‐Purpose Auxetic Foam with Honeycomb Concave Micropattern for Sound and Shock Energy Absorbers
Authors: Kim Ji‐Seok , Mahato Manmatha , Oh Jung‐Hwan , Oh Il‐Kwon
Published: December 2022

Porous materials have been widely used for passive energy absorption in various applications including aerospace systems, automotive vehicles, and electronic products, due to high energy dissipation and sound absorbing mechanism in a wide frequency band. However, most porous materials have a critical problem in poor mechanical properties that inhibit their application to shock absorbing structures. Herein, a multi‐purpose auxetic structure is reported that has a highly ordered honeycomb concave micropattern on the surface of the auxetic foam through non‐solvent induced phase separation. Most importantly, the dimensions of the concave micropatterns can be easily controlled depending on the non‐solvent ratio. The energy absorption performance and mechanical strength are significantly enhanced by adopting concave micropatterns on the curved surface in the auxetic foam. The superior energy absorption performances of the multi‐dimensional auxetic foam are improved by 37.5% in view of an average sound absorption coefficient, and the improved mechanical properties are verified by systematically investigating porous properties such as tortuosity, porosity, apparent density, and total pore area. In addition, the proposed multi‐purpose auxetic foam exhibits a remarkably improved shock energy dissipation capacity, which reduces impact force by 34% compared with that of bare polyurethane foam in a low‐velocity impact test.
Multiscale Engineering of Sustainable and Versatile All‐Fiber Triboelectric Nanogenerator Based on Multifunctional Fibrous Materials and 3D Woven Architecture
Authors: Tian Xiao , Hua Tao , Yang Mengyan , Niu Ben , Yang Yiyi
Published: December 2022

With the development of energy‐harvesting fabrics, woven structured textile‐based triboelectric nanogenerators (T‐TENGs) are widely proposed. However, most T‐TENGs with woven structures consist of one material, which greatly limits the functionality of T‐TENGs. This work focuses on structural design and rational material configuration to realize versatility of woven‐structured T‐TENG by a green, eco‐friendly, scalable production method. A 3D triboelectric nanogenerator fabric (3D SP‐FTENG) is proposed, which performs excellent electrical output (27.33 V, 1.76 µA, and 61.6 mW m−2) and wearability (directional water transport and breathability) as well as antibacterial activity. Moreover, in contrast to the previously reported multilayer T‐TENGs which are constructed by directly stacking multilayer functional fabrics together, the fabric interface of this new structure fabricated by weaving the support area and the functional area together is not easily delaminated. The 3D SP‐FTENG demonstrates outstanding durability (machine washability and ultrahigh abrasion resistance). In addition, the SP‐FTENG is able to drive wearable electronics and be used as a self‐powered sensor, such as constantly monitoring the movement signals of human body. This study presents a novel and sustainable strategy for the development of eco‐friendly multifunctional T‐TENGs.
3D Structural Electronics Via Multi‐Directional Robot 3D Printing
Authors: Bao Chao , Moeinnia Hadi , Kim Tae‐Ho , Lee Wonchul , Kim Woo Soo
Published: December 2022

Multi‐material 3D printing is an innovative technology that sparks a revolution in combined structural 3D printing with different functional materials. However, current multi‐material printing systems work alone and cannot take full advantage of each printing, and the limited freedom of existing 3D printers confines diversity of structural designs. Here, a double‐arm robotic 3D printing system combined with paste‐based direct ink writing (DIW) and filament‐based fused filament fabrication (FFF) is reported as a new fabrication solution for customized 3D structural electronics. Collaboration between two robot arms brings about a spontaneous sintering effect of metal nano‐particles (minimum resistance = 14.5 Ω per 10 mm) by addition of the following extruded layer through FFF for the fabrication of embedded sensors, which reduces the post‐processing steps and saves energy for sintering compared with the conventional parallel multi‐material 3D printing processes. The extra freedom of motions from two robot‐arm 3D printing enables multi‐directional curvilinear printing for 3D structural electronics, such as a double‐helix‐shaped embedded sensor. In addition, precise robot motion enables the electrical registration and vertical integration of multi‐layered printed circuit boards. Establishment of new double‐robot 3D printing system expands design freedom and realization of 3D structural electronics.
High‐Permittivity Polysiloxanes for Solvent‐Free Fabrication of Dielectric Elastomer Actuators
Authors: von Szczepanski Johannes , Opris Dorina M.
Published: December 2022

Dielectric elastomer actuators (DEAs) are a class of soft transducers with broad potential applications in soft robotics. DEAs consist of two stretchable electrodes on a dielectric elastomer, which deform and generate force when charged. The generated force is increased by placing many DEAs on top of one another to form a stack actuator. Next‐generation stack actuators require high permittivity inks that are solvent‐free processable and cross‐linkable into thin elastic films. Here, a process toward elastomers with tuneable permittivity that can be prepared solvent‐free is reported. Polycondensation of chlorosilanes yields polymers with vinyl end‐groups and cross‐linkers with multiple hydrosilane groups that both carry polar chloromethyl groups. Their dielectric permittivity and mechanical properties are tuned by changing the polar group content and the molar mass of the vinyl‐terminated polymer, respectively. Solvent‐free doctor blading provides thin films, which are cross‐linked by heating. DEAs prepared from the films reach a lateral actuation of promising 4.6% at a low electric field of 11.2 V µm‐1 and can be operated at frequencies up to 5 Hz. The high‐permittivity polymer ink is used in a solvent‐free layer‐by‐layer stack actuator fabrication, which yields an actuator with three active layers that gives a thickness strain of 1.0% at 12.4 V µm‐1.
Enhancing Luminescence Efficiency by Controlled Island Formation of CsPbBr3 Perovskite
Authors: Antrack Tobias , Kroll Martin , Merten Lena , Albaladejo‐Siguan Miguel , Hinderhofer Alexander , Konovalov Oleg V. , Jankowski Maciej , Benduhn Johannes , Schreiber Frank , Vaynzof Yana , Leo Karl
Published: December 2022

CsPbBr3 is an inorganic perovskite material that is promising for light‐emitting applications. Such applications are known to benefit from an island‐type active layer structure, which enhances the device's light emission efficiency. Here, the impact of the environment on the island formation in thermally deposited bilayers of CsPbBr3/LiBr is investigated. It is demonstrated that the island formation occurs only in humid environments, leading to an enhancement of the photoluminescence quantum yield by a factor of 350. Time‐resolved grazing‐incidence wide‐angle X‐ray scattering experiments document the island growth process and reveal that the LiBr has already changed the perovskite crystal orientation prior to the island formation.
Dual Promotion of Phosphorus Groups for Ultralong Room Temperature Phosphorescence with High Efficiency
Authors: Zhou Yuanlin , Qu Lunjun , Yi Shuang , Wang Chang , Chen Xiaohong , Tang Shiman , Tang Hailong , Li Youbing , Wang Kaiti , Zhao Yanli , Yang Chaolong
Published: December 2022

Organic room temperature phosphorescence (RTP) materials have drawn wide attention due to their dynamic phosphorescence performance under ambient conditions. However, most of the pure organic RTP materials show low phosphorescence efficiency and short lifetime because of their weak spin–orbit coupling and fast nonradiative decay process. Introducing halogen heavy atoms can effectively improve the efficiency, while the lifetime would be shortened obviously. Thus, there is still a great challenge especially for developing halogen heavy atom free organic RTP materials, with simultaneously enhanced phosphorescence efficiency and lifetime. Herein, it is demonstrated that triphenylphosphine group possesses a strong n‐electron donating character and adopts a rigid tetrahedral configuration, which are in favor of accelerating intersystem crossing process and suppressing the nonradiative decay process, respectively. Benefited from the dual promotion of triphenylphosphine group, the obtained compound named CzPhP shows a decent phosphorescence efficiency of 14.36% and a prolonged lifetime of 340 ms. Another three pentavalent phosphine‐bearing analogs synthesized, i.e., CzPhPO, CzPhPS, and CzPhPSe, also present different conformational aggregations and good RTP performance. The diversity of the RTP performance of these compounds affords a potential application in anticounterfeiting and data encryption.
High Photoresponsivity and Response Speed of Visible‐Light Photodetectors Based on Tin Disulfide/Indium‐Doped Tin Disulfide Homostructures
Authors: Liu Zhe , Jia Xiyu , Duan Weishuai , Zhu Xinfa , He Biao , Sun Chun , Wang Mengjun , Li Erping , Fan Chao
Published: December 2022

Tin disulfide (SnS2) is an emerging 2D‐layered metal dichalcogenide with promising application potential for highly sensitive and fast‐response‐speed photodetectors. However, SnS2‐based photodetectors still have drawbacks that limit their practical and commercial applications. Herein, an effective route is proposed for constructing SnS2/indium‐doped SnS2 homostructures to improve photodetector performance. Vertical SnS2/Sn0.991In0.009S2 homostructures and photodetectors based on these homostructures were fabricated via a polydimethylsiloxane‐assisted dry‐transfer method. The photodetectors exhibit excellent performance, including a high photoresponsivity of up to 271.7 A W−1, high normalized detectivity of up to 2.13 × 1012 cm Hz1/2 W−1, and fast response time of ≈10 ms. The pseudo‐built‐in electrical field of the SnS2/Sn0.991In0.009S2 homostructure results in the superior performance of the photodetectors based on this material compared to that based on individual SnS2 and Sn0.991In0.009S2 thin layers, most 2D materials, and commercial photodetectors (e.g., THORLABS FD11A Si, and FGA01 InGaAs). This study provides a facile and effective approach to enhance the performance of SnS2‐based photodetectors and paves the way for future applications of photodetectors based on SnS2 and other 2D materials.
PMMA Optical Diffusers with Hierarchical Surface Structures Imprinted by Hot Embossing of Laser‐Textured Stainless Steel
Authors: Bouchard Felix , Soldera Marcos , Lasagni Andrés Fabián
Published: December 2022

Increasingly compact and powerful light emitting diodes require the development of efficient optical diffusers to manage their lighting capability according to the required application. In this study, a cost‐effective strategy is demonstrated for fabricating micro‐structured polymethylmethacrylate (PMMA) diffusers for white light sources. By combining different laser‐based processes, namely direct laser engraving (DLE), direct laser writing (DLW), and direct laser interference patterning (DLIP), periodic patterns are fabricated in stainless steel surfaces with line‐ and dot‐like geometries with feature sizes ranging from 1.7 to 900 µm. The fabricated hierarchical geometries are transferred to PMMA surfaces by plate‐to‐plate hot embossing. The relationship between the surface topography and the white light scattering behavior is investigated by confocal and scanning electron microscopy combined with photospectroscopy and image processing of photographs. The triple‐scaled hierarchical structures can increase the haze up to 76% in the visible spectrum, while keeping the total transmittance over 90%, as the flat surface.
LiNaB6O9F2: A Promising UV NLO Crystal Having Fluorine‐Directed Optimal Performances and Double Interpenetrating 3[B6O9F2]∞ Networks
Authors: Li Xiaojing , Chen Zilong , Li Fuming , Zhang Fangfang , Yang Zhihua , Pan Shilie
Published: December 2022

A long‐lasting challenge in ultraviolet (UV) nonlinear optical (NLO) materials design is to combine conflicting and harsh properties into one structure, including wide UV transparency, strong NLO efficiency, and moderate birefringence to realize phase‐matching at short wavelength. A fluorine‐directed material design strategy is adopted to accelerate the process of finding NLO materials with optimal performances. In this work, taking LiB3O5 (LBO) as a maternal structure, one O atom with two F atoms is substituted and LiNaB6O9F2 which possesses novel double interpenetrating 3[B6O9F2]∞ networks and fluorine‐directed optimal performances including enhanced birefringence and phase‐matching capacity is successfully obtained. The perfect balance among deep‐UV cutoff edge, large second‐harmonic generation (SHG) response (1.1 × KDP), and moderate birefringence (0.067 at 1064 nm) of LiNaB6O9F2 makes it a promising UV NLO crystal.
Hydrogen‐Assisted Synthesis of Large‐Size 2D Bismuth Telluride Flakes for Broadband Photodetection up to 2 µm
Authors: Zhao Tiange , Zhong Fang , Wang Shicheng , Wang Yingke , Xu Tengfei , Chen Yue , Yu Yiye , Guo Jiaxiang , Wang Zhen , Yu Jiancan , Gao Pingqi
Published: December 2022

Broadband photodetection including optical communication wavelength band is of great significance because of the great potential for various civilian and military applications. Topological insulators with unique surface electronic states have attracted more and more attention in broadband photodetection. Among them, due to its suitable band gap (0.16–1.36 eV), ultra‐high mobility, and excellent air stability, 2D bismuth telluride (Bi2Te3) is regarded as a promising candidate. However, the growth of large‐size Bi2Te3 is challenging because of the poor chemical reactivity of tellurium (Te) element. Here, large‐scale (240 µm, ten times larger than the current record) Bi2Te3 flakes with controllable thickness (one to few layers) are successfully synthesized by H2‐assisted chemical vapor deposition. Thanks to the strong reducibility and the passivation on the substrate of H2, the growth rate is as high as 48 µm min−1, which is ten times faster than that reported. Moreover, the Bi2Te3‐photodetector exhibits broadband detection (520–2000 nm), high responsivity of 252 A W−1, excellent detectivity of 5.1 × 1011 cm Hz1/2 W−1, and fast response time (τrise/τdecay ≈ 41/38 ms), implying potential applications in broadband optoelectronics. More importantly, this work may pave a way for the rapid growth of other novel large‐scale 2D materials.
Mn5+ Lifetime‐Based Thermal Imaging in the Optical Transparency Windows Through Skin‐Mimicking Tissue Phantom
Authors: Piotrowski Wojciech M. , Marin Riccardo , Szymczak Maja , Martín Rodríguez Emma , Ortgies Dirk H. , Rodríguez‐Sevilla Paloma , Dramićanin Miroslav D. , Jaque Daniel , Marciniak Lukasz
Published: December 2022

Lifetime‐based luminescence thermometry has been shown to enable accurate deep‐tissue monitoring of temperature changes – even at the in vivo level – in a minimally invasive way. However, major limiting factors to the performance of this approach are short lifetimes and poor brightness. These are characteristics, respectively, of semiconductor nanocrystals and lanthanide‐doped nanoparticles, of which most luminescent nanothermometers are made. To address these limitations, the composition of luminescent nanothermometers co‐doped with transition metal (Mn5+) and Er3+ ions are designed and optimized. The salient features of these nanothermometers are strong, near‐infrared emission and long, temperature‐dependent photoluminescence lifetime. The potential of these luminescent nanophosphors for thermal sensing is then showcased by monitoring a thermal gradient using a one‐of‐a‐kind piece of equipment designed for lifetime‐based luminescence thermometry measurements. The combination of the newly developed nanothermometers and the custom‐made instrument allows for obtaining 2D thermal maps both in the absence and presence of tissue phantoms mimicking the optical properties of the skin. The results presented in this study thus provide credible foundations for the deployment of lifetime‐based thermometry for accurate deep‐tissue thermal mapping at the preclinical level.
Divergent Neural Activity in the VLPO During Anesthesia and Sleep
Authors: Luo Mengqiang , Fei Xiang , Liu Xiaotong , Jin Zikang , Wang Yingwei , Xu Min
Published: December 2022

The invention of general anesthesia (GA) represents a significant advance in modern clinical practices. However, the exact mechanisms of GA are not entirely understood. Because of the multitude of similarities between GA and sleep, one intriguing hypothesis is that anesthesia may engage the sleep‐wake regulation circuits. Here, using fiber photometry and micro‐endoscopic imaging of Ca2+ signals at both population and single‐cell levels, it investigates how various anesthetics modulate the neural activity in the ventrolateral preoptic nucleus (vLPO), a brain region essential for the initiation of sleep. It is found that different anesthetics primarily induced suppression of neural activity and tended to recruit a similar group of vLPO neurons; however, each anesthetic caused comparable modulations of both wake‐active and sleep‐active neurons. These results demonstrate that anesthesia creates a different state of neural activity in the vLPO than during natural sleep, suggesting that anesthesia may not engage the same vLPO circuits for sleep generation.