Article
Engineering, Mechanical
Liron Agmon, Roy Almog, Dana Gaspar, Guy Voscoboynik, Meenakshi Choudhary, Juergen Jopp, Ziv Klausner, Assaf Ya'akobovitz, Ronen Berkovich
Summary: This study investigates the nanoscale mechanical contact interaction of MoS2 monolayers with Au and Si using adhesion measurements and friction force microscopy. The results demonstrate stronger adhesive interaction and friction forces between MoS2 and Au, suggesting their potential importance in applications such as coatings, sensors, and mechanoelectrical devices.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Chemistry, Physical
Yalan Li, Li Jiang, Yanqiu Zou, Zhengbo Song, Shangzhong Jin
Summary: A novel SERS sensor is proposed for detecting low concentrations of GSH in human serum, utilizing a dense monolayer film of self-assembly Au Nano cubes to enhance Raman spectroscopy through electrostatic interaction. The sensor shows a linear relationship between the relative spectral intensity of TNB characteristic peak and the concentration of GSH between 50 and 750 nM, with a detection limit of 50 nM. The SERS substrate used in the sensor is easy to prepare, highly uniform, and reproducible, offering potential for clinical applications in sensitive and quantitative detection of trace analytes.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Mechanical
S. Hemette, J. Cayer-Barrioz, D. Mazuyer
Summary: The experimental analysis of the friction response of an ice-rubber interface over a wide range of sliding velocities and temperatures was conducted, identifying adhesive and viscoelastic contributions based on in-situ contact area measurements. Despite observing a bell-shaped friction-velocity curve, a classical WLF transform could not adequately describe the friction behavior. A simple analytical model considering thermal dissipation induced by friction was proposed, leading to a dimensionless master curve that accounts for sliding velocity independent of temperature and material properties.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Chemistry, Physical
Lu Liu, Yang Yang, Minyong Du, Yuexian Cao, Xiaodong Ren, Lu Zhang, Hui Wang, Shuai Zhao, Kai Wang, Shengzhong (Frank) Liu
Summary: This article investigates the interface issues of wide-bandgap perovskite solar cells and successfully improves energy conversion efficiency and indoor efficiency by designing a self-assembled monolayer as the interface layer. In addition, an all-perovskite tandem solar cell is configured, and a decent power conversion efficiency is achieved.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Iris Berg, Luca Schio, Justus Reitz, Elena Molteni, Linoy Lahav, Carolina Gutierrez Bolanos, Andrea Goldoni, Cesare Grazioli, Guido Fratesi, Max M. Hansmann, Luca Floreano, Elad Gross
Summary: In this study, the self-assembly of N-heterocyclic olefins (NHOs) on gold surface was investigated using experimental and computational methods. It was found that NHOs can self-assemble into dimers, trimers, and tetramers, forming stable monolayers. The study also revealed that NHOs can adsorb on gold surface in a flat-lying geometry through coordination with gold adatoms, and the surface interaction can be further increased by functionalizing the backbone with methyl groups, leading to enhanced thermal stability and impact on work-function values.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Mechanical
Deliang Zhang, Yuge Zhang, Qiang Li, Mingdong Dong
Summary: The study found that environmental adsorbates play an important role in load-dependent friction hysteresis in graphene, leading to a positive friction hysteresis. After the removal of environmental adsorbates, a negative friction hysteresis was observed.
Article
Physics, Applied
Kai Takeuchi, Junsha Wang, Beomjoon Kim, Tadatomo Suga, Eiji Higurashi
Summary: The surface activated bonding (SAB) technique allows room temperature bonding of metals by forming metal bonds between clean and reactive surfaces. However, re-adsorption on the activated surface decreases the bonding quality, limiting its applicability for electronics packaging. This study proposes and demonstrates the prolongation of surface activation effect for room temperature bonding of Au using a self-assembled monolayer (SAM) protection. The surface analysis shows that the clean and activated Au surface is protected from re-adsorption by SAM, allowing for time-independent bonding of Au at room temperature.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Naomi Deneke, Jamie A. Booth, Edwin P. Chan, Chelsea S. Davis
Summary: In this study, a pressure-tunable adhesive (PTA) based on self-assembly of microscale asperities was developed to achieve controllable adhesion strength. The adhesion strength of the PTA can be increased by applying compressive preload, and the pull-off force can be controlled by adjusting the preload. This approach is scalable and applicable to different material systems.
ADVANCED MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Cun-hong Yin, Chen Yang, Yu-zhong Wu, Yi-long Liang, Zhen-long Zhu
Summary: In this study, a novel nanocomposite self-lubricating oxide surface composed of amorphous structures and oxide nanoparticles was discovered. The formation process and mechanism were demonstrated, and the improved tribological and wear properties of the surface were observed.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Nathanael C. Ramos, J. Will Medlin, Adam Holewinski
Summary: The stable electrochemical potential window of thiolate self-assembled monolayers (SAMs) on Au, Pt, and Cu electrodes is studied systematically in aqueous electrolyte systems. The reductive stability is found to depend on the binding strength of sulfur and competitive adsorption of hydrogen, while the oxidative stability is related to each surface's propensity toward surface oxide formation. The stability of SAMs is also influenced by factors such as SAM defects, intermolecular interactions, SAM thickness, and the ability to directly oxidize or reduce the non-sulfur part of the SAM molecule.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Ruisong Wang, Karan Jakhar, Shoaib Ahmed, Dion S. Antao
Summary: Research investigates the mechanism of organofunctional silane SAM coating degradation during water vapor condensation and finds that coatings prepared in a dry environment exhibit superior long-term robustness.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Yurong Zhao, Xuzhi Hu, Limin Zhang, Dong Wang, Stephen M. King, Sarah E. Rogers, Jiqian Wang, Jian R. Lu, Hai Xu
Summary: Controlling the dimension of nanostructures self-assembled from short peptides remains a challenge, with peptide bolaamphiphiles forming nanotubes due to the interplay between side chain structure and hydrophobicity; changes in amino acid side chain structure can significantly impact nanostructure formation, with the introduction of hydroxyl groups alleviating steric hindrance.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Thermodynamics
Ruisong Wang, Jiahui Guo, Emily A. Muckleroy, Dion S. Antao
Summary: Dropwise condensation can improve heat transfer performance, but existing coatings are prone to degradation. By improving the preparation process of silane coatings, better durability and heat transfer performance can be achieved.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Analytical
Marcin Gwiazda, Sheetal K. Bhardwaj, Ewa Kijenska-Gawronska, Wojciech Swieszkowski, Unni Sivasankaran, Ajeet Kaushik
Summary: This research presents an electrochemical immunosensor for collagen I detection using stable covalent immobilization of gold nanoparticles and enzymatically reduced antibodies, achieving high sensitivity in the range of pg/mL. The sensor's unique advantage lies in the appropriate orientation of antibodies onto the surface, good stability, and selectivity properties, with a detection range of 1 to 5 pg/mL.
Article
Biochemical Research Methods
Jingya Li, Qianqian Wang, Juan Wang, Man Li, Xiang Zhang, Longlong Luan, Pan Li, Weiping Xu
Summary: The study developed a quantitative SERS sensor based on gold-silver heterogeneous nanocuboids for detecting pesticides on agricultural produce and pollutants in fishpond water. Chemically functionalized densely packed Au@Ag NCs monolayer exhibited high SERS performance.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2021)
Article
Materials Science, Ceramics
Kuo-Chin Hsu, Bo-Da Chen, Te-Hua Fang, Chao-Ming Hsu
Summary: In this study, tungsten oxide (WO3) nanofibers were prepared using electrospinning technology and combined with La0.8Pb0.2FeO3 (LPFO) perovskite materials to form a heterostructure film for gas sensing applications. The pure WO3 nanofiber gas sensor showed excellent sensing for nitrogen dioxide (NO2) and hydrogen sulfide (H2S), while the WO3/LPFO heterostructure film gas sensor exhibited a high response to H2S but suppressed response to NO2. The WO3/LPFO heterostructure film gas sensor greatly improved gas selectivity, with specific sensitivity towards H2S gas.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Yu-Sheng Lu, Te-Hua Fang
Summary: The aspect ratio has a significant effect on buckling instability, with the critical buckling stress decreasing as the aspect ratio increases. Molecular dynamics simulation shows that the NiCoCr medium-entropy alloy nanotubes exhibit instability when the aspect ratio reaches 10. Single-crystalline specimens have higher compressive strength compared to polycrystalline specimens.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Physical
Thi-Xuyen Bui, Te-Hua Fang, Chun-I. Lee
Summary: The effects of different inclusion types, inclusion radius, and strain rates on the mechanical properties of NiFeCr alloy were investigated through molecular dynamic simulation. It was found that increasing strain rates led to an increase in tensile strength, strain energy, and dislocation densities. Samples without inclusions had higher tensile strength, strain energy, and dislocation densities compared to samples with inclusions. The inclusion radius had a complex effect, with decreasing Young's modulus for all inclusion types. The phase transformations and dislocation lengths were larger in samples without inclusions, and Stair-rod and Shockley partial dislocations were dominant in all samples.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Hoang-Giang Nguyen, Te-Hua Fang, Dinh-Quan Doan
Summary: The impact of temperature and strain rates on the cyclic plasticity of AlCrCuFeNi high entropy alloy (HEA) was investigated using molecular dynamics (MD) simulations. The results revealed that interactions between partial dislocations in the HEA caused lattice disorders, which minimized the Bauschinger effect. The study also highlighted the influence of temperature, strain rates, and grain boundaries on lattice disorder and provided new insights into the deformation mechanism of AlCrCuFeNi HEA.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Thi-Bao-Tien Tran, Te-Hua Fang, Dinh-Quan Doan
Summary: Nowadays, stacking 2D van der Waals heterostructures, such as GaSe and graphene, provides more opportunities for designing optoelectronic devices. We created GaSe/Graphene heterostructures with various defect lines and studied their mechanical properties using molecular dynamics simulations. We found that the mechanical properties of GaSe/Graphene heterostructures can be greatly enhanced through defect engineering, and the potential applications include stretchable electronics and supercapacitor devices.
MECHANICS OF MATERIALS
(2023)
Article
Physics, Condensed Matter
Chia-Wei Huang, Tang-Yu Lai, Te-Hua Fang, Shih-Wei Liang
Summary: With the rapid development of science and technology, the use of solid lubricants, particularly Molybdenum disulfide (MoS2), in microscale machining has gained significant attention. Molecular dynamics simulations were conducted to investigate the influence of scratch depth, speed, and temperature on the mechanical properties of Ni-based MoS2 thin films. The results revealed that higher scratch depths, speeds, and temperatures led to increased friction coefficients and wider dislocation distributions, with the appearance of Shockley dislocation in all cases.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Man-Ping Chang, Te-Hua Fang, Ting-Yu Zhu, Jau-Wen Lin
Summary: In this study, the mechanical properties and deformation mechanisms of CoCrFeNiMnx high entropy alloys (HEAs) were investigated through molecular dynamics (MD) simulation. Uniaxial tensile tests were conducted at different temperatures and manganese compositions, and a circular defect was created to study the damage tolerance of these HEAs. The results showed that the CoCrFeNiMn HEA exhibited a strong temperature dependence, with the ultimate tensile strength decreasing as the temperature increased. The early stage deformation was dominated by dislocation slip, while grain boundary glide played a major role in the later stage deformation. The higher manganese content led to the formation of hexagonal close-packed (HCP) and amorphous phases, which reduced the strength of CoCrFeNiMnx HEAs. Among the compositions tested, Mn5 HEA showed the best damage tolerance.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Automation & Control Systems
Duy-Khanh Nguyen, Te-Hua Fang, Yu-Cheng Fan, Ching-Chien Huang, Chu-Xun Lin
Summary: This paper investigates the influence of control parameters of a pneumatic valve-controlled dispenser on the positional accuracy and reliability of liquid droplets, and finds that flow rate has the most impact on both criteria. Additionally, using a small needle can significantly improve the quality.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Chemistry, Physical
Thi-Nhai Vu, Van-Trung Pham, Te-Hua Fang
Summary: The deformation properties and mechanical behavior of the lamellar twined Al0.3CoCrFeNi high-entropy alloys (HEA) sample were studied using molecular dynamics (MD) simulations. The results showed different mechanical characteristics under different twin inclination angles and strain rates. It was also found that the flow stress, ultimate strength, and Young's modulus increased with increasing strain rate and decreasing temperature.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Chih-Chieh Mo, Chih-Cheng Kuan, Yung-Hsiang Wang, Yu-Sheng Lu, Tsung-Wei Chang, Wei-Yu Liao, Te-Hua Fang, Mi-Ching Tsai, Ching-Chien Huang
Summary: This study demonstrates an innovative and effective method for recycling waste NdFeB magnets by preparing recycled sintered NdFeB magnets on a large scale. By adding NdCoGa alloy to waste wind turbine NdFeB magnets, the proposed process restores the magnetic properties of the recycled magnets to the level of the original waste magnets, enhances their corrosion resistance, and reduces the cost of magnet remanufacturing.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Thi-Thuy Binh Ngo, Van-Thuc Nguyen, Te-Hua Fang
Summary: This study uses molecular dynamics (MD) simulation to investigate the mechanical characteristics and deformation behavior of Cu material under nanoscratching using a diamond tooltip on the workpiece. The effects of scratching velocity, scratching depth, workpiece temperature, and grain size on various parameters are studied.
JOURNAL OF MOLECULAR MODELING
(2023)
Article
Materials Science, Multidisciplinary
Hoang-Giang Nguyen, Te-Hua Fang
Summary: The mechanical behavior of AlCuNiTi alloy during orthogonal micro-cutting is investigated using molecular dynamics. The results show that the sample temperature is higher during complex-dimensional vibration cutting (CDVC) compared to classical cutting, and the cutting force decreases with increasing vibration frequency and amplitude ratio.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Duy-Khanh Nguyen, Te-Hua Fang, Yue-Ru Cai, Ching-Chien Huang
Summary: This work utilizes molecular dynamics simulation to investigate the machining mechanism and deformation behavior of NiFeCo during conventional nanoscale cutting and ultrasonic elliptical vibration-assisted cutting (UEVC). The study reveals that under UEVC, there are higher magnitudes of local stress, temperature, and shear strain, and the distribution of stacking fault and dislocation is more influenced by grain boundaries. Furthermore, increasing the vibration frequency and reducing the amplitude ratio positively impact the material removal rate and average cutting force.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Physics, Condensed Matter
Van-Trung Pham, Thi-Nhai Vu, Te-Hua Fang, Duc-Binh Luu, Van-Thanh Hoang, Ngoc-Hai Tran, Minh-Sang Tran, Quang-Bang Tao
Summary: Molecular dynamics simulations were used to analyze the mechanical behavior of FeNiCrCoCu high-entropy alloys (HEA) during nanoimprint lithography with different structures. The study found that microstructure and vibration parameters significantly affected the loading force, elastic recovery ratio, and deformation behavior. The results showed that the maximum loading force decreased in the order of single-crystal, nano-twinned polycrystal, and polycrystalline structures. Grain size variation in the polycrystalline structure revealed an inverse Hall-Petch relationship. Grain boundaries played a crucial role in material softening, with grain splitting, migration, and rotation being the main deformation mechanisms. Twin boundaries in the nano-twinned polycrystal enhanced material stability and their migration was explored near the imprinted region. The best formability was observed in specimens with a grain size of 9.8 nm in the polycrystalline structure, with a smaller elastic recovery ratio and better forming shape. A mold angle of 10 degrees and 20 degrees resulted in a symmetrical pattern shape, indicating better-imprinted shape compared to other angles. The study also analyzed the effect of high-frequency mechanical vibration and found that the best forming ability was achieved with a vibration amplitude of 3.0 & ANGS;. Changing vibration frequencies showed that a frequency of 50 GHz provided the highest forming ability.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Hoang-Giang Nguyen, Te-Hua Fang
Summary: The deformation mechanism and evolutionary patterns of mechanical behavior in the Alx(CuCrFeNi)1_x high-entropy alloy during nanoindentation are investigated using molecular dynamics. The study reveals that the mechanical attributes and structural changes are influenced by temperature, grain size, and alloy composition. An increase in the Al percentage leads to a reduction in the indentation force, and the concentration of aluminum and larger grain sizes enhance the overall ductility of the alloys. The movement of mobile prismatic dislocations significantly contributes to the deformation process.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)