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A Miniaturized CMOS-MEMS Amperometric Gas Sensor for Rapid Ethanol Detection

IEEE Sensors Journal 2023年第8期23卷 8128-8137页

作者： Thu, Do Thi Liu, Zong-Han Lee, Ya-Chu Kuo, Tzu-Wen Sung, Wei-Lun Chu, Yen-Chang Chueh, Yu-Lun Fang, Weileun Institute of NanoEngineering and MicroSystem National Tsing Hua University Department of Power Mechanical Engineering Department of Materials Science and Engineering Hsinchu30013 Taiwan Hsinchu Science Park PixArt Imaging Inc. Hsinchu30076 Taiwan

This study presents the design and implementation of a chip-scale amperometric ethanol sensor using the standard commercially available complementary metal oxide semiconductor (CMOS) process together with the post-CMOS micromachining processes. The presented amperometric sensor consists of a suspended plate with a microhole structure as the working electrode, a fully anchored plate with a microhole structure as the counter electrode, and a microcavity as the electrolyte reservoir. The metal and dielectric layers inherent in the standard CMOS process are exploited to realize these structures. The electrode with a microhole structure could enhance its surface area to improve the sensitivity of the sensor. The suspended working electrode covered a thinner Nafion R layer could facilitate gas diffusion to shorten the response time of the sensor. To characterize the ethanol sensing, a Ni film is deposited on the working electrode. Measurements indicate the presented sensor has a sensing range of ppm (20-1000 ppm) at room temperature. Moreover, its sensitivity and response time are, respectively, 0.01 nA/ppm and 6 s. The presented design shows the CMOS-MEMS is a promising approach to realize the amperometric ethanol sensor. © 2001-2012 IEEE.

关键词： Electrolytes

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Role of Microstructural Heterogeneity on Nanoscale mechanical Properties and Wear Responses of Additively Manufactured CoCrNi Medium Entropy Alloy and 316L Stainless Steel

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Journal of materials engineering and Performance 2024年第12期33卷 5717-5726页

作者： Vashishtha, Himanshu Kumar, Deepak Kim, You Sub Lee, Soo Yeol Huang, E-Wen Jain, Jayant Department of Materials Science and Engineering Indian Institute of Technology Delhi New Delhi110016 India School of Metallurgy and Materials University of Birmingham BirminghamB15 2TT United Kingdom Department of Mechanical Engineering Carnegie Mellon University 5000 Forbes Ave PittsburghPA15213 United States Department of Materials Science and Engineering Chungnam National University Daejeon34134 Korea Republic of Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsin-Chu30013 Taiwan

In the present study, a systematic comparison of additively manufactured CoCrNi medium entropy alloy having face-centered-cubic (FCC) structure with standard FCC materials 316L austenitic stainless steel was carried out. The effect of energy density (71 J/mm2) on microstructural heterogeneity and crystallographic orientation of planes parallel to the build direction (X–Z) and perpendicular to the build direction (X–Y) was recorded. Scanning electron microscopy, x-ray diffraction and electron backscattered diffraction techniques were used to reveal the surface and structural features. The effect of repetitive heating associated with layer-by-layer deposition of the X–Z axis was reflected as the favorable formation of the (1 1 1) plane at the expense of the (2 2 0) plane. The low angle grain boundaries at the X–Z axis have been decreased by ~ 27% compared to the X–Y axis for CoCrNi, while a ~ 17% reduction was recorded for 316L austenitic stainless steel. Furthermore, the decreasing trends in nanomechanical properties and wear resistance were observed, with a low number of low angle grain boundaries at the X–Z axis, by employing a nanoindenter. Significant microcracks in CoCrNi medium entropy alloy manifest the brittle fracture mode, whereas 316L alloy denotes the mixed type of failure mode. © ASM International 2023.

关键词： Cobalt alloys

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Regulating the radical intermediates by conjugated units in covalent organic frameworks for optimized lithium ion storage

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Journal of Energy Chemistry 2022年第6期31卷 428-433,I0012页

作者： Shuai Gu Xiaoxia Ma Jingjing Chen Rui Hao Zhiqiang Wang Ning Qin Wei Zheng Qingmeng Gan Wen Luo Muqing Li Zhiqiang Li Kemeng Liao Hao Guo Guiyu Liu Kaili Zhang Zhouguang Lu Department of Materials Science and Engineering Shenzhen Key Laboratory of Interfacial Science and Engineering of MaterialsGuangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and DevicesSouthern University of Science and TechnologyShenzhen 518055GuangdongChina Department of Mechanical Engineering City University of Hong KongKowloonHong Kong 999077China

Organic active units often transform into radical intermediates during the redox processes but exhibit poor cycling stability due to the uncontrollable redox of the radicals. Herein, we report a facile and efficient strategy to modulate the molecular orbital energies, charge transport capacities, and spin electron densities of the active units in covalent organic frameworks(COFs) via regulating the conjugated unit size to optimize the redox activity and stability of the organic radicals. COFs based on different imide conjugated units exhibit tunable discharge voltages, rate performance and cycling stabilities. Detailed characterizations and theoretical calculation reveal that imide radicals are the important active intermediates during the redox processes of these COFs. Specifically, increasing the size of the imide conjugated units could effectively delocalize the radical electrons and improve the stability of the COFs electrodes. This study offers a very effective strategy to modulate the redox chemistry of organic materials for electrochemical energy storage.

关键词： Organic electrodes Radical intermediates Covalent organic frameworks

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Effect of Surface Roughness on the Magnetism, Nano-indentation, Surface Energy, and Electrical Properties of Co60Fe20Dy20 Films on Si (100) Substrate

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Journal of Electronic materials 2024年第4期53卷 1752-1762页

作者： Liu, Wen-Jen Chang, Yung-Huang Chiang, Chia-Chin Chen, Yuan-Tsung Lin, Chih-Chien Chen, Pei-Ling Lin, Shih-Hung Department of Materials Science and Engineering I-Shou University Kaohsiung840 Taiwan Bachelor Program in Industrial Technology National Yunlin University of Science and Technology 123 University Road Section 3 Yunlin Douliou64002 Taiwan Department of Mechanical Engineering National Kaohsiung University of Science and Technology Kaohsiung City80778 Taiwan Graduate School of Materials Science National Yunlin University of Science and Technology 123 University Road Section 3 Yunlin Douliou64002 Taiwan Department of Electronic Engineering National Yunlin University of Science and Technology 123 University Road Section 3 Yunlin Douliou64002 Taiwan

In this study, we focused on depositing a target material, cobalt-iron-dysprosium (Co60Fe20Dy20), onto silicon (Si) (100) substrates with thickness varying from 10 nm to 50 nm through a direct-current (DC) magnetron sputtering technique. The subsequent step involved subjecting the samples to an hour-long annealing process in a vacuum annealing furnace at temperatures of 100°C, 200°C, and 300°C. To assess the elemental composition of the CoFeDy films, energy-dispersive X-ray spectroscopy (EDS) was employed. An observed trend indicated an increase in low-frequency alternating-current magnetic susceptibility (χac) with the increasing thickness. Remarkably, the CoFeDy films exhibited their peak χac following annealing at 300°C, with an optimal resonance frequency of 50 Hz. After annealing at 300°C, the CoFeDy film’s surface energy peaked at 50 nm. The magnetic, electrical, and adhesive properties of the CoFeDy films were notably influenced by surface roughness at different annealing temperatures. Atomic force microscopy (AFM) analysis revealed a gradual reduction in film roughness post-annealing, corresponding to smoother surfaces indicative of a weaker domain wall pinning effect, heightened carrier conductivity, and increased liquid spreading. Collectively, these outcomes contributed to diminished χac, reduced electrical resistance, and enhanced adhesion. Graphical Abstract: (Figure presented.) © The Minerals, Metals & materials Society 2024.

关键词： Adhesion

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Scalable synthesis of hcp ruthenium-molybdenum nanoalloy as a robust bifunctional electrocatalyst for hydrogen evolution/oxidation

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Journal of Energy Chemistry 2022年第9期31卷 176-185,I0006页

作者： Zhen Zhang Haijun Liu Liwen Ni Zhi-Liang Zhao Hui Li School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Department of Materials Science and Engineering Shenzhen Key Laboratory of Hydrogen EnergySouthern University of Science and TechnologyShenzhen 518055GuangdongChina Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055GuangdongChina

The hydrogen evolution reaction(HER)is the cathodic process of water splitting,and its reverse,the hydrogen oxidation reaction(HOR),is the anodic process of an H-Ofuel cell;both play important roles in the development of hydrogen *** rational design and scalable fabrication of low-cost and efficient bifunctional catalysts for the HER/HOR are highly ***,ultrasmall Mo-Ru nanoalloy(Mo_(0.5)Ru_(3)and Mo_(0.5)Ru_(3))particles uniformly distributed on mesoporous carbon(MPC)were successfully synthesized by a simple method that is easy to scale up for mass *** the incorporation of Mo atoms,the as-prepared Mo_(0.5)Ru_(3)and Mo_(0.5)Ru_(3)nanoalloys maintain a hexagonal-close-packed crystal *** acidic media,Mo_(0.5)Ru_(3)exhibits excellent Pt-like HER and HOR activity,as well as good *** functional theory(DFT)calculations reveal that the H adsorption free energy(ΔG)on the Mo_(0.5)Ru_(3)(001)surface(-0.09 eV)is much closer to zero than that of metallic Ru(-0.22 eV),which contributes to the enhanced catalytic *** alkaline media,Mo_(0.5)Ru_(3)also presents outstanding HER and HOR activity,even significantly outperforming Pt/*** DFT results confirm that optimal binding energies with H*and OH*intermediate species,and low energy barriers in the water dissociation and formation steps,efficiently accelerate the alkaline HER/HOR kinetics of Mo_(0.5)Ru_(3).This study provides a new avenue for the scalable fabrication of high-efficiency bifunctional electrocatalysts for the HER and HOR in both acidic and alkaline media.

关键词： Hydrogen evolution reaction Hydrogen oxidation reaction Ruthenium Water splitting Fuel cell

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Electronic structure regulation of Fe-doped Ni2P nanocrystals towards durable electrocatalytic oxygen evolution

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Rare Metals 2024年第12期43卷 6405-6415页

作者： Ya Liu Xing Cao Jia-Jia Liu Mei-Sheng Han Gao-Wei Zhang Yu-Bin Zhao Huan-Hui Chen Liang Yu Jun-Rong Zeng Zhi-Kai Cheng Liu-Biao Zhong Li-Juan Song Ye-Jun Qiu Shenzhen Engineering Lab of Flexible Transparent Conductive Films School of Materials Science and EngineeringHarbin Institute of TechnologyShenzhen518055China School of Physics Harbin Institute of TechnologyHarbin150001China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen518055China School of Science Harbin Institute of TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic Systems Harbin Institute of TechnologyShenzhen518055China

The inherent electrocatalytic potential of transition metal phosphides(TMPs)for oxygen evolution is influenced by the reduced efficiency of electron transfer resulting from the interaction between electronegative phosphorus atoms and transition ***,we introduce Fe into Ni_(2)P nanocrystals by thermal injection synthesis method,and anchor them on nickel foam(NF)by facile spraying to prepare self-supporting oxygen evolution reaction(OER)***,the optimized electrode of Ni_(2)P-Fe-2/NF demonstrates low overpotentials of 212 mV with 10 mA·cm^(-2)and a 0.9%decay within300 h test of 50 mA·cm^(-2).Notably,when electrode size was expanded to 600 cm^(2)and applied to a larger electrolyzer,its 9 h decay rate at 6 A current was only 1.69%.Characterization results show that Fe doped NiOOH is generated during OER reaction as actual catalyst,Results from density functional theory(DFT)computations suggest that Fe doping shifts NiOOH d-band center to Fermi level,lowering critical *OOH intermediates formation energy barrier during the OER *** findings inform the large-scale industrial application of TMPs as robust electrocatalysts.

关键词： Electronic structure regulation Fe doping Colloidal nanocrystals Ni2P Oxygen evolution reaction

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Comparative Evaluation of Stress Concentration Generated on Human Femur Structure Using Meshfree Software 12th

Comparative Evaluation of Stress Concentration Generated on ...

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12th International Workshop of Advanced Manufacturing and Automation, IWAMA 2022

作者： Adugna, Yosef W. Lemu, Hirpa G. Department of Mechanical and Structural Engineering and Materials Science University of Stavanger Stavanger Norway

ISBN: (纸本)9789811993374

Norway is one of the countries with the highest registered incidence of hip fractures in the world. About 60% of the hip fractures are in the femoral neck, few in the caput and the rest are in the trochanteric region, called trochanteric, pertrochanteric or intertrochanteric fractures. Numerical modeling allows the study of the bone mechanical behavior and the prediction of different trauma caused by accidents without exposing humans to real tests. In this work, structural analysis is carried out on femur bone which is modeled from a CT scan DICOM file and material properties are assigned. Loading conditions are based on the force which exerts on the femur during the daily routine activities. The analysis is carried out with two different boundary conditions and vertical loads of 25 kg, 35 kg, 70 kg, 125 kg, and 200 kg applied in both conditions. Two finite element software programs (ABAQUS® and ANSYS®) and meshless software (SimSolid®) were used to compare these results. They exhibited similar behavior in regions with the highest concentrations of mechanical stress. The use of meshless software Simsolid proved to be effective at detecting higher stress levels considering different factors that exist in biomechanical simulations. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Finite element method

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Sparse identification-assisted exploration of the atomic-scale deformation mechanism in multiphase CoCrFeNi high-entropy alloys

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science China(Technological sciences) 2024年第4期67卷 1124-1132页

作者： XIAO Lu GUO XiaoXiang SUN YuTong WANG Gang LONG WeiMin LIAW Peter K. REN JingLi School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Institute of Materials Shanghai UniversityShanghai 200444China SKL of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(HEAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase HEA was prepared using molecular dynamics simulation involving melt and quench *** HEA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-packed structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi HEA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

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Shape Memory Alloy Reinforced Self-Healing Aluminum Composites for Energy Conservation

Shape Memory Alloy Reinforced Self-Healing Aluminum Composit...

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Advances in Sustainable Composites: Eco-friendly Solutions and Applications was part of the 154th Annual Meeting and Exhibition, TMS 2025

作者： Bellah, Masum Srivastava, Vaibhav Nosonovsky, Michael Church, Benjamin Rohatgi, Pradeep Department of Mechanical Engineering University of Wisconsin-Milwaukee MilwaukeeWI United States Department of Materials Science and Engineering University of Wisconsin-Milwaukee MilwaukeeWI United States

ISBN: (纸本)9783031810565

engineering components are frequently discarded after they develop cracks, requiring replacement with new high embodied energy components. In this paper, self-healingSelf-healingaluminumAluminum matrix compositesComposite with the capability of self-healing are discussed. These compositesComposite can self-heal cracks, thereby extending component life and conserving energy by reducing the need for replacements. Research on aluminumAluminum alloy compositesComposite reinforced by shape memory alloys is presented, including the narrowing and closing of cracks, the recovery of strength, and shape restoration in these alloys. The microstructures of these self-healingSelf-healing alloy compositesComposite and the mechanics and kinetics of self-healing, including the rate of crack narrowing and closing and the rate of shape restoration, are also reportedBiomimetics. © The Minerals, Metals & materials Society 2025.

关键词： Cracks

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Quasiparticle and excitonic properties of monolayer 1T′ WTe2 within many-body perturbation theory

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Physical Review B 2024年第7期110卷 075133-075133页

作者： Jinyuan Wu Bowen Hou Wenxin Li Yu He Diana Y. Qiu Department of Mechanical Engineering and Materials Science Department of Applied Physics

In the monolayer limit, 1T′ WTe2 is a two-dimensional topological insulator exhibiting the quantum spin Hall effect and is believed to host an excitonic insulator ground state. However, theoretical analysis of this system is complicated by the difficulty of obtaining descriptions of the single-quasiparticle band structure consistent with experimental measurement within conventional first-principles techniques. Previous band-structure calculations using the Perdew-Burke-Ernzerhof functional and a one-shot GW approximation result in a semimetallic band structure, while calculations with hybrid functionals appear to open a band gap. Here, we demonstrate that self-consistently updating wave functions within a static GW approximation (static COHSEX) can reproduce the insulating band structure experimentally observed by angle-resolved photoemission spectroscopy without resorting to mechanisms beyond the quasiparticle picture. Finally, a finite-momentum Bethe-Salpeter equation calculation on top of self-consistent GW results in negative exciton excitation energies, leaving open the possibility of excitonic instability in 1T′ monolayer WTe2.

关键词： 2-dimensional systems Transition metal dichalcogenides Bethe-Salpeter equation Density functional calculations GW method

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