http://www.mdpi.com/journal/materials/special_issues/spm-in-materials/ Dear Colleagues, This special issue will focus on recent advances in the field of materials science and engineering facilitated by the use of scanning probe microscopy (SPM) instrumentation and methodologies. Example of topics within the scope of this issue include; studies of the nanoelectronic and magnetic properties of materials, nanoscale dynamic mechanical properties of materials, single cell mechanics and mechanotransduction, integration of SPM with chemical characterization techniques, atomic manipulation, high resolution imaging of biological materials and engineered tissues, nanoscale tribology, friction, lubrication, wear, nanoscale adhesion, atomic force microscope-based nanoindentation, single molecule force spectroscopy, and spatially specific nanomechanics. Dr. Christine Ortiz Guest Editor Submission All manuscripts should be submitted to materials@mdpi.com with a copy to the Guest Editor. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website. Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed Open Access monthly journal published by MDPI. Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this Open Access journal is 800 CHF per accepted paper. http://www.mdpi.com/1996-1944/3/9/4668/ With the advancement of the field of biotribology, considerable interest has arisen in the study of cell and tissue frictional properties. From the perspective of medical device development, the frictional properties between a rigid surface and underlying cells and tissues are of a particular clinical interest. As with many bearing surfaces, it is likely that contact asperities exist at the size scale of single cells and below. Thus, a technique to measure cellular frictional properties directly would be beneficial from both a clinical and a basic science perspective. In the current study, an atomic force microscope (AFM) with a 5 µm diameter borosilicate spherical probe simulating endovascular metallic stent asperities was used to characterize the surface frictional properties of vascular smooth muscle cells (VSMCs) in contact with a metallic endovascular stent. Various treatments were used to alter cell structure, in order to better understand the cellular components and mechanisms responsible for governing frictional properties. The frictional coefficient of the probe on VSMCs was found to be approximately 0.06. This frictional coefficient was significantly affected by cellular crosslinking and cytoskeletal depolymerization agents. These results demonstrate that AFM-based lateral force microscopy is a valuable technique to assess the friction properties of individual single cells on the micro-scale. http://www.mdpi.com/1996-1944/3/9/4668/ Tue, 14 Sep 2010 00:00:00 CEST Materials 2010-09-14 3 9 Article 4668 4680 1996-1944 Frictional Behavior of Individual Vascular Smooth Muscle Cells Assessed By Lateral Force Microscopy 2010-09-14 doi: 10.3390/ma3094668 Delphine Dean Jason Hemmer Alexey Vertegel Martine LaBerge http://www.mdpi.com/1996-1944/3/9/4518/ Nano-structuring of the surface caused by adsorption of molecules or atoms and by the reaction of surface atoms with adsorbed species are reviewed from a chemistry viewpoint. Self-assembly of adsorbed species is markedly influenced by weak mutual interactions and the local strain of the surface induced by the adsorption. Nano-structuring taking place on the surface is well explained by the notion of a quasi-molecule provided by the reaction of surface atoms with adsorbed species. Self-assembly of quasi-molecules by weak internal bonding provides quasi-compounds on a specific surface. Various nano-structuring phenomena are discussed: (i) self-assembly of adsorbed molecules and atoms; (ii) self-assembly of quasi-compounds; (iii) formation of nano-composite surfaces; (iv) controlled growth of nano-materials on composite surfaces. Nano-structuring processes are not always controlled by energetic feasibility, that is, the formation of nano-composite surface and the growth of nano-particles on surfaces are often controlled by the kinetics. The idea of the “kinetic controlled molding” might be valuable to design nano-materials on surfaces. http://www.mdpi.com/1996-1944/3/9/4518/ Fri, 27 Aug 2010 00:00:00 CEST Materials 2010-08-27 3 9 Review 4518 4549 1996-1944 Surface Nano-Structuring by Adsorption and Chemical Reactions 2010-08-27 doi: 10.3390/ma3094518 Ken-ichi Tanaka http://www.mdpi.com/1996-1944/3/8/4277/ Dynamic behavior of signal transmission through metal complexes [L5M-BL-ML5]5+ (M=Fe, Ru, Os, BL=pyrazine (py), 4,4’-bipyridine (bpy), L=NH3), which are simplified models of the molecular quantum-dot cellular automata (molecular QCA), is discussed from the viewpoint of one-electron theory, density functional theory. It is found that for py complexes, the signal transmission time (tst) is Fe(0.6 fs) < Os(0.7 fs) < Ru(1.1 fs) and the signal amplitude (A) is Fe(0.05 e) < Os(0.06 e) < Ru(0.10 e). For bpy complexes, tst and A are Fe(1.4 fs) < Os(1.7 fs) < Ru(2.5 fs) and Os(0.11 e) < Ru(0.12 e) <Fe(0.13 e), respectively. Bpy complexes generally have stronger signal amplitude, but waste longer time for signal transmission than py complexes. Among all complexes, Fe complex with bpy BL shows the best result. These results are discussed from overlap integral and energy gap of molecular orbitals. http://www.mdpi.com/1996-1944/3/8/4277/ Fri, 06 Aug 2010 00:00:00 CEST Materials 2010-08-06 3 8 Article 4277 4290 1996-1944 Metal Dependence of Signal Transmission through MolecularQuantum-Dot Cellular Automata (QCA): A Theoretical Studyon Fe, Ru, and Os Mixed-Valence Complexes 2010-08-06 doi: 10.3390/ma3084277 Ken Tokunaga http://www.mdpi.com/1996-1944/3/8/4252/ Since the invention of scanning tunneling microscopy (STM), 2D supramolecular architectures have been observed under various experimental conditions. The construction of these architectures arises from the balance between interactions at the medium-solid interface. This review summarizes molecular motion observed in 2D-supramolecular structures on surfaces using nanospace resolution STM. The observation of molecular motion on surfaces provides a visual understanding of intermolecular interactions, which are the major driving force behind supramolecular arrangement. http://www.mdpi.com/1996-1944/3/8/4252/ Fri, 06 Aug 2010 00:00:00 CEST Materials 2010-08-06 3 8 Review 4252 4276 1996-1944 Molecular Dynamics in Two-Dimensional Supramolecular Systems Observed by STM 2010-08-06 doi: 10.3390/ma3084252 Shinobu Uemura Ryota Tanoue Neval Yilmaz Akihiro Ohira Masashi Kunitake http://www.mdpi.com/1996-1944/3/8/4196/ Scanning probe microscopy (SPM) techniques have had a great impact on research fields of surface science and nanotechnology during the last decades. They are used to investigate surfaces with scanning ranges between several 100 mm down to atomic resolution. Depending on experimental conditions, and the interaction forces between probe and sample, different SPM techniques allow mapping of different surface properties. In this work, scanning tunneling microscopy (STM) in air and under electrochemical conditions (EC-STM), atomic force microscopy (AFM) in air and scanning electrochemical potential microscopy (SECPM) under electrochemical conditions, were used to study different single crystalline surfaces in electrochemistry. Especially SECPM offers potentially new insights into the solid-liquid interface by providing the possibility to image the potential distribution of the surface, with a resolution that is comparable to STM. In electrocatalysis, nanostructured catalysts supported on different electrode materials often show behavior different from their bulk electrodes. This was experimentally and theoretically shown for several combinations and recently on Pt on Au(111) towards fuel cell relevant reactions. For these investigations single crystals often provide accurate and well defined reference and support systems. We will show heteroepitaxially grown Ru, Ir and Rh single crystalline surface films and bulk Au single crystals with different orientations under electrochemical conditions. Image studies from all three different SPM methods will be presented and compared to electrochemical data obtained by cyclic voltammetry in acidic media. The quality of the single crystalline supports will be verified by the SPM images and the cyclic voltammograms. Furthermore, an outlook will be presented on how such supports can be used in electrocatalytic studies. http://www.mdpi.com/1996-1944/3/8/4196/ Thu, 05 Aug 2010 00:00:00 CEST Materials 2010-08-05 3 8 Article 4196 4213 1996-1944 STM, SECPM, AFM and Electrochemistry on Single Crystalline Surfaces 2010-08-05 doi: 10.3390/ma3084196 Holger Wolfschmidt Claudia Baier Stefan Gsell Martin Fischer Matthias Schreck Ulrich Stimming http://www.mdpi.com/1996-1944/3/7/3965/ Confinement of electrons can occur in metal islands or in continuous films grown heteroepitaxially upon a substrate of a different metal or on a metallic alloy. Associated quantum size effects (QSE) can produce a significant height-dependence of the surface free energy for nanoscale thicknesses of up to 10–20 layers. This may suffice to induce height selection during film growth. Scanning STM analysis has revealed remarkable flat-topped or mesa-like island and film morphologies in various systems. We discuss in detail observations of QSE and associated film growth behavior for Pb/Cu(111), Ag/Fe(100), and Cu/fcc-Fe/Cu(100) [A/B or A/B/A], and for Ag/NiAl(110) with brief comments offered for Fe/Cu3Au(001) [A/BC binary alloys]. We also describe these issues for Ag/5-fold i-Al-Pd-Mn and Bi/5-fold i-Al-Cu-Fe [A/BCD ternary icosohedral quasicrystals]. Electronic structure theory analysis, either at the level of simple free electron gas models or more sophisticated Density Functional Theory calculations, can provide insight into the QSE-mediated thermodynamic driving force underlying height selection. http://www.mdpi.com/1996-1944/3/7/3965/ Fri, 09 Jul 2010 00:00:00 CEST Materials 2010-07-09 3 7 Review 3965 3993 1996-1944 Nanoscale “Quantum” Islands on Metal Substrates: Microscopy Studies and Electronic Structure Analyses 2010-07-09 doi: 10.3390/ma3073965 Yong Han Bariş Ünal Dapeng Jing Patricia A. Thiel James W. Evans Da-Jiang Liu http://www.mdpi.com/1996-1944/3/6/3675/ The relationship between the electrocatalytic properties of an electrode and its ability to transfer electrons between the electrode and a metallic tip in a scanning tunneling microscope (STM) is investigated. The alkaline oxygen evolution reaction (OER) was used as a test reaction with four different metallic glasses, Ni78Si8B14, Ni70Mo20Si5B5, Ni58Co20Si10B12, and Ni25Co50Si15B10, as electrodes. The electrocatalytic properties of the electrodes were determined. The electrode surfaces were then investigated with an STM. A clear relationship between the catalytic activity of an electrode toward the OER and its tunneling characteristics was found. The use of a scanning tunneling spectroscope (STS) in electrocatalytic testing may increase the efficiency of the optimization of electrochemical processes. http://www.mdpi.com/1996-1944/3/6/3675/ Mon, 14 Jun 2010 00:00:00 CEST Materials 2010-06-14 3 6 Article 3675 3693 1996-1944 Scanning Tunneling Spectroscope Use in Electrocatalysis Testing 2010-06-14 doi: 10.3390/ma3063675 Knutsen