Article
Physics, Fluids & Plasmas
P. C. Torche, P. Nicolini, T. Polcar, O. Hovorka
Summary: This paper highlights the importance of developing the thermodynamics of nanoscale friction and demonstrates how modern stochastic thermodynamics can help interpret measurements obtained by friction force microscopy. It shows that heat produced during the friction process serves as an unambiguous measure of thermodynamic irreversibility, with velocity-dependent scaling behavior observed in a broad velocity range.
Article
Engineering, Chemical
Lei Zhan, Yitian Peng, Yao Huang, Kun Zou
Summary: In this study, the friction properties of graphene as a solid lubricant in micro-/nano-electromechanical system components were investigated using atomic force microscopy. It was found that the friction coefficient of graphene changed from positive to negative during the unloading process on different thicknesses of graphene. The turning point of friction coefficient was not affected by the unloading range but increased with the thickness of graphene. Different stick-slip behaviors were observed, indicating that the out-of-plane deformation of graphene is the main reason for these frictional characteristics. The anomalous friction at the contact interface between the microsphere probe and graphene expands the understanding of the frictional properties of graphene.
Article
Engineering, Electrical & Electronic
Tomohiro Komatsu, Yukino Nishikawa, Shota Shima, Yuji Uchiyama, Eiichi Kobayashi, Eiichiro Takamura, Hiroaki Sakamoto
Summary: The demand for sensors that detect falling events in aged people, infants, and toddlers is increasing. Conventional acceleration sensors are susceptible to false recognition, so a novel fall-detecting sensor using triboelectric nanogenerator (TENGs) is proposed, which effectively detects falls by measuring the impact pressure.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Biochemistry & Molecular Biology
Alexander Ukraintsev, Mikhail Kutuzov, Ekaterina Belousova, Marie Joyeau, Victor Golyshev, Alexander Lomzov, Olga Lavrik
Summary: Genome compaction is an important research field for understanding gene expression, DNA replication, and repair mechanisms. Nucleosomes are the basic units of DNA compaction in eukaryotic cells. While the main chromatin proteins responsible for DNA compaction have been identified, the regulation of chromatin architecture is still extensively studied. This study used atomic force microscopy to investigate the interactions between three PARPs and nucleosomes, revealing that PARP3 significantly alters the geometry of nucleosomes, potentially suggesting a new role for PARP3 in chromatin compaction regulation.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Editorial Material
Multidisciplinary Sciences
Meghna Krishnadas
Summary: Neighbouring plants play a role in shaping the performance of their own species and other species. Understanding how these interactions change with rainfall can help explain patterns of plant diversity and predict responses to global environmental change.
Article
Materials Science, Composites
Zitong Guo, Zhongde Shan, Jihua Huang, Dong Wang, Hao Huang, Debo Xue, Zhuojian Hou
Summary: This study investigated the frictional behavior of Z-yarn during implantation into a preform to reduce wear and tear. By designing a guiding array clamping device and a tensile force sensor, changes in tensile strength of Z-yarns at different implantation positions and times were studied. Results showed that the use of unadulterated solvent dimethyl silicone oil and a tension control system effectively reduced wear and increased the continuous implantation number of Z-yarns.
POLYMER COMPOSITES
(2022)
Article
Chemistry, Multidisciplinary
Jae Hwan Jeong, Yeonjoon Jung, Jang-Ung Park, Gwan-Hyoung Lee
Summary: This study investigates the gate-tunable electrostatic friction of grain boundaries (GBs) in chemically vapor deposition (CVD)-grown MoS2 films. It is found that the electrostatic friction is generated by the Coulomb interaction between the tip and the carriers of MoS2, which is related to the localized band structure of GBs. The results show a strong correlation between electrostatic friction and localized band structure, providing a novel method for identifying and characterizing GBs in polycrystalline 2D materials.
Article
Engineering, Mechanical
Fitsum B. Tewelde, Tianfeng Zhou, Jia Zhou, Weijia Guo, Bin Zhao, Xiangyu Ge, Wenzhong Wang, Xiaoli Wang, Xibin Wang
Summary: This study examined the impact of asymmetric surface texturing on directional friction in a dry environment. Asymmetric micro-grooves were created on an electroless nickel phosphorous (Ni-P) plated disk using a diamond cutting process. Sliding tests were conducted in both clockwise (CW) and counter-clockwise (CCW) directions against polyether-ether-ketones (PEEK) material at various texture densities. The results indicate that asymmetric surface texturing has a significant effect on directional friction. At a texture density of 70%, the friction coefficient in the CW direction increased by 28.1% compared to the CCW direction. The lowest texture density caused a 61.3% increase in friction coefficient during CW rotation compared to the reference untextured surface.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Antoine Laine, Andrea Vanossi, Antoine Nigues, Erio Tosatti, Alessandro Siria
Summary: In this study, an experimental and simulation approach was used to investigate the successive live phases of atomic scale friction by applying an oscillatory shear force with increasing amplitude. The demonstration with controlled gold nanocontacts sliding on graphite revealed phenomena bridging the gap between initial depinning and large speed sliding.
Article
Optics
Yizhe Zhao, Yilin Su, Xuyan Hou, Minghui Hong
Summary: This study explores the feasibility of producing a bionic superhydrophobic stainless steel surface through laser precision engineering, allowing directional superhydrophobicity and dynamic water transportation control. The dynamic mechanism of water sliding on hierarchical snake scale structures is studied, providing key insights for reproducing artificially bioinspired multifunctional materials.
OPTO-ELECTRONIC ADVANCES
(2021)
Article
Engineering, Mechanical
Yunfeng Wang, Minjuan He, Wenhao He, Yuan Niu, Zhibin Lu
Summary: In this study, the effects of atomic relaxation on the friction properties in h-BN/h-BN and Gr/Gr interface systems were investigated. It was found that under lower pressures, the effects of atomic relaxation on the friction force could be ignored, while they were significant under higher pressures.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Chemistry, Physical
Omid Bavi, Farhad Ghadak
Summary: New atomic-scale fabrication methods have enabled scientists to design and manufacture nanostructured devices for the investigation and application of nanoscale regimes in fluid mechanics. Different conditions, such as fluid velocity, surface material, and geometry of nanoscale roughness, lead to significant differences in the atomic interaction of airflow/solid surfaces. These findings shed light on designing aerophobic surface coatings for a wide range of applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Engineering, Mechanical
Haoyu Yin, Wei Wu, Kwang Leong Choy
Summary: By introducing the degree of freedom for the substrate and using graphene as an example, this study investigates the friction between atomic layers. The simulations provide a clear understanding of the relative motions between the sensing sheet and the substrate, leading to a better understanding of atomic layer friction.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Chemistry, Multidisciplinary
Harry S. Geddes, Henry D. Hutchinson, Alex R. Ha, Nicholas P. Funnell, Andrew L. Goodwin
Summary: By using the non-negative matrix factorisation (NMF) approach, the study demonstrates how the pair distribution function (PDF) of complex mixtures can be separated into contributions from individual phase components and interfaces between phases, focusing specifically on a model system Fe parallel to Fe3O4. The experimental results show excellent agreement with theoretical predictions, highlighting the significance of this method in characterising interfaces in complex functional materials.
Article
Chemistry, Multidisciplinary
Niklas A. Weber, Hendrik Schmidt, Tim Sievert, Christian Jooss, Friedrich Guethoff, Vasily Moshneaga, Konrad Samwer, Matthias Krueger, Cynthia A. Volkert
Summary: This study investigates the mechanism of friction at sliding contacts, proposing that friction can be explained by considering the damping of stick-slip pulses. The findings provide a basis for reconciling controversies in literature studies on friction and suggest possible tactics for controlling friction.
Article
Chemistry, Multidisciplinary
Kalyan Biswas, Jose I. Urgel, M. R. Ajayakumar, Ji Ma, Ana Sanchez-Grande, Shayan Edalatmanesh, Koen Lauwaet, Pingo Mutombo, Jose M. Gallego, Rodolfo Miranda, Pavel Jelinek, Xinliang Feng, David Ecija
Summary: This study reports the successful on-surface synthesis of the largest pristine member of the n-PA family, peri-heptacene, on an Au(111) substrate under ultra-high vacuum conditions. High-resolution scanning tunneling microscopy and theoretical simulations provide insights into the chemical structure of this previously elusive compound. Scanning tunneling spectroscopy reveals that peri-heptacene exhibits an antiferromagnetic open-shell singlet ground state and a singlet-triplet spin-flip inelastic excitation with an effective exchange coupling of 49 meV.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xunshan Liu, Adam Matej, Tim Kratky, Jesus Mendieta-Moreno, Sebastian Guenther, Pingo Mutombo, Silvio Decurtins, Ulrich Aschauer, Jascha Repp, Pavel Jelinek, Shi-Xia Liu, Laerte L. Patera
Summary: In this study, selective C-H activation of hexaazatriphenylene by Scholl reaction was reported for the first time, achieving dehydrogenative C-C couplings. The formation of one-dimensional polymers with a double-chain structure was revealed using low-temperature scanning tunneling microscopy and atomic force microscopy. Density functional theory calculations rationalized the growth process, highlighting the cooperative catalytic action of Na and Ag adatoms in steering the C-H selectivity for polymerization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Physics, Multidisciplinary
Thomas Hofmann, Xinguo Ren, Alfred J. Weymouth, Daniel Meuer, Alexander Liebig, Andrea Donarini, Franz J. Giessibl
Summary: This study presents a method for the transition from graphite to diamond on the atomic scale and reveals the local rehybridization of the structure during this transition. The experimental observation of harmonics at specific thresholds and force reduction provides evidence for the existence of this transition.
NEW JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Physical
Alexander Liebig, Christoph Setescak, Adrian Weindl, Franz J. Giessibl
Summary: This study utilizes high-resolution atomic force microscopy to observe and analyze surface defects in Bi2Se3. The researchers find that all Se vacancies have a positive polarity, confirming them as electron donors. This work provides a new method for accurately determining the physical properties of defects in topological insulators.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Kalyan Biswas, Diego Soler, Shantanu Mishra, Qiang Chen, Xuelin Yao, Ana Sanchez-Grande, Kristjan Eimre, Pingo Mutombo, Cristina Martin-Fuentes, Koen Lauwaet, Jose M. Gallego, Pascal Ruffieux, Carlo A. Pignedoli, Klaus Mullen, Rodolfo Miranda, Jose I. Urgel, Akimitsu Narita, Roman Fasel, Pavel Jelinek, David Ecij
Summary: This study explores three families of nanographenes (A, B, and C) and finds that open-shell nanographenes exhibit the strongest magnetic exchange coupling, especially near the transition from closed-shell to open-shell states. Experimental results confirm the predictions, and two specific nanographenes show record values of magnetic exchange coupling measured on the Au(111) surface, close to 200 meV. This research provides insights for designing carbon nanomaterials with robust magnetic ground states.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Federico Frezza, Frederik Schiller, Ales Cahlik, Jose Enrique Ortega, Johannes V. Barth, Andres Arnau, Maria Blanco-Rey, Pavel Jelinek, Martina Corso, Ignacio Piquero-Zulaica
Summary: In this study, quinoidal ligands were reacted with single cobalt atoms on an Au(788) surface in ultra-high vacuum, resulting in the formation of cobalt-quinoid chains. The electronic structure of these chains was investigated using angle-resolved photoemission spectroscopy, and their narrow bandgap structure was revealed using low-temperature scanning tunneling microscopy/spectroscopy. Theoretical calculations confirmed that the observed electronic bands originated from the efficient hybridization of cobalt and molecular orbitals. This work provides a foundation for the systematic search of similar one-dimensional π-d hybridized metal-organic chains with tunable electronic and magnetic properties.
News Item
Chemistry, Multidisciplinary
P. Jelinek
Summary: An organic quantum magnet has been created by synthesizing short chains of porphyrin derivatives on a surface and manipulating atoms using a scanning probe microscope tip.
Article
Nanoscience & Nanotechnology
Alfred J. Weymouth, Emily Roche, Franz J. Giessibl
Summary: This study investigates the effect of an electron donor on the electronic state by studying mixed islands of PTCDA and CuPc. The results show that the 2DEG state disappears and new states emerge under submonolayer coverage.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Tao Wang, Paula Angulo-Portugal, Alejandro Berdonces-Layunta, Andrej Jancarik, Andre Gourdon, Jan Holec, Manish Kumar, Diego Soler, Pavel Jelinek, David Casanova, Martina Corso, Dimas G. de Oteyza, Jan Patrick Calupitan
Summary: The coupling of a sterically demanded pentacene derivative on Au(111) into fused dimers connected by non-benzenoid rings was studied using high-resolution scanning tunneling microscopy/spectroscopy and density functional theory. The diradical character of the products was tuned by modifying the coupling section, with the antiaromaticity of cyclobutadiene and its position within the structure playing a significant role. Understanding these structure-property relationships is crucial for designing new complex and functional molecular structures.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Andrea Auer, Bernhard Eder, Franz J. Giessibl
Summary: This paper presents a combined AFM/STM instrument realized with a qPlus sensor and a home-built potentiostat for electrochemical applications. It demonstrates the potential of the instrument by simultaneously imaging graphite with atomic resolution in acidic electrolytes and precisely measuring the interfacial solvent layering as a function of the applied potential.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Theresa Seeholzer, Daniela Tarau, Lea Hollendonner, Andrea Auer, Reinhard Rachel, Dina Grohmann, Franz J. Giessibl, Alfred J. Weymouth
Summary: Researchers compared the S-layer proteins extracted from the archaeon Pyrobaculum aerophilium using atomic force microscopy (AFM) in liquid and ambient conditions with transmission electron microscopy (TEM) images under vacuum conditions. Improved AFM scanning and sample preparation methods allowed the observation of the crystalline structure of the S-layer samples.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Physics, Multidisciplinary
Norio Okabayashi, Thomas Frederiksen, Alexander Liebig, Franz J. Giessibl
Summary: This study reveals the complete manipulation process of a CO molecule on a Cu(110) surface using a combination of noncontact atomic force microscopy and density functional theory simulations. An intermediate state crucial for understanding dynamic friction is found in the reaction pathway during manipulation.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Norio Okabayashi, Thomas Frederiksen, Alexander Liebig, Franz J. Giessibl
Summary: Friction, a complex phenomenon, is studied by simplifying the system through molecular manipulation. In this paper, the authors use noncontact atomic force microscopy, inelastic electron tunneling spectroscopy, and density functional theory calculations to investigate the molecular manipulation process of a single CO molecule on Cu(110) and Cu(111) surfaces. They discover the presence of an important adsorption site that plays a role in the manipulation process and contributes to understanding the dynamics of manipulation and dynamic friction.