Bare Wire Research Articles

Simulation study on the effect of palladium layer thickness and temperature on the bonding properties of palladium coated copper wire

Palladium coated copper (PCC) wire is an emerging bonding wire. There are relatively few studies on the effect of palladium plating thickness and temperature on its bonding performance. In order to investigate the effects of three parameters, namely palladium plating thickness, chip preheating temperature and the free air ball (FAB) initial temperature, on the bonding performance of PCC wires, this paper establishes a transient nonlinear finite element analysis model of thermal coupling between bare copper wires and PCC wires, and simplifies the whole bonding process into two stages of impact and ultrasonic vibration to carry out the experimental simulation. Firstly, the Taguchi orthogonal test method was adopted to obtain the ranking of the degree of influence of the three factors on the bonding results, and the optimum palladium plating thickness and FAB initial temperature of 100 nm and 100 °C were derived, respectively. Then the PCC wires with 100 nm palladium plating thickness were selected, and the bare copper wires were used as the reference, and multiple one-factor simulation experiments were carried out under the condition of changing the chip preheating temperature only. The simulation results show that the FAB and pad stress levels in the bonding results of the PCC wires are significantly higher than those of the bare copper wires, but the GaN layer stress is less than that of the bare copper wires. Moreover, there is an approximate parabolic relationship between the maximum stresses of pad and GaN layer and the preheating temperature of the chip. In the bonding results of bare copper wire, there is also an approximate parabolic relationship between the maximum stress of FAB and the chip preheating temperature. This parabolic relationship allows a prediction of the optimum chip preheating temperature. Selecting the appropriate palladium plating thickness and controlling the appropriate FAB temperature and chip preheating temperature can improve the bonding quality, and this numerical simulation work can provide a reference for the selection of palladium plating thickness and temperature parameter regulation of PCC wires.

Comparison of subcooled flow boiling in concentric annuli with bare and finned surfaces

In this study, the hydrodynamic and thermal characteristics of subcooled flow boiling in concentric annuli with inner heating wires, featuring bare and finned surfaces designed for heat transfer enhancement, were experimentally investigate, with a focus on cooling technology for EV charging cables. The bare wire test module consisted of a 300 mm long wire, with a 290 mm long inner heating surface and a diameter of 10 mm. The outer tube was constructed from transparent polycarbonate with a 22 mm diameter, allowing optical access to observe the flow. The finned wire test module has an identical construction, except for the addition of six longitudinally extruded fins with cross-sectional dimensions of 2 × 5 mm2. Experiments and flow visualizations, aided by high speed imaging, were conducted using HFE-7100 as the working fluid at mass velocities, G, 463.7 to 1,309.6 kg/m2s and heat fluxes from 0.90 to 9.93 W/cm2, under inlet pressures between 120 and 240 kPa. The study investigated thermal non-equilibrium phenomena, driven by asymmetric bubble accumulation, and their effects on circumferential temperature distribution, which showed opposing trends between the bare and finned surfaces. An evaluation of previous empirical correlations for predicting subcooled flow boiling heat transfer coefficients was performed, followed by an assessment of fin performance in enhancing heat transfer. A comparative analysis with the bare surface module of the same dimensions confirmed that the longitudinal fins provided superior thermal management, maintaining the surface temperature below the safety threshold, Ts,safe. The longitudinal fins demonstrated a 54.5 % reduction in charging time and a 183.7 % increase in charging current for charging up to 80 % state of charge (SOC) of a 77.4 kWh battery, compared to the bare wire.

Oxidized Ethylene Glycol/ZrO2-coated NiTi Orthodontic Arch Wires: Surface Characterization and Electrochemical and Corrosion Studies

Background: Orthodontic arch wires, typically made of Nickel Titanium (NiTi), are widely utilized in dental procedures for correcting teeth misalignment and jaw issues due to their favorable mechanical attributes and cost-effectiveness. However, these NiTi wires are prone to corrosion in the oral environment, leading to diminished mechanical stability, compromised aesthetics, and potential health concerns for patients. Objective: There is a growing demand to augment the corrosion resistance and stability of orthodontic wires. Hence, this study aimed to address these issues. Herein, zirconium dioxide (ZrO2) and oxidized ethylene glycol (OEG) films were deposited onto NiTi wires to improve the corrosion resistance and stability. Methods: NiTi wires were modified by a two-step process involving electrodeposition of ZrO2 and oxidized ethylene glycol (OEG) film. The surface characterizations of coated material (OEG/ZrO2/NiTi) were carried out by using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), and Electron Microprobe Analysis (EMap) to confirm the elemental composition of the coated NiTi wire. Results: The OEG/ZrO2/NiTi wire exhibited a potentiodynamic polarization resistance of 547037 Ω and higher stability than the bare NiTi wire (396421 Ω). The corrosion rate for OEG/ZrO2/NiTi wire was found to be 0.040 mm/year, which was comparatively lower than a bare NiTi wire (0.069 mm/year). Due to the formation of OEG/ZrO2 film, NiTi wire became electrically insulative and showed a higher impedance than bare NiTi wire. Conclusion: The bilayer coating of ZrO2 and OEG has proven to significantly improve the corrosion resistance and stability of the wires. Thus, these materials can be considered for coating orthodontic arch wires with improved corrosion stability.

Experimental and theoretical research on the temperature evolution law of overcurrent fault wires

AbstractTo investigate the problems of overload and excessive thermal insulation associated with building electrical fires caused by wires, a theoretical model of wire heat transfer is established, and the pyrolysis and combustion phenomena of the insulation layer are analyzed. The results showed that the temperature evolution of the wire underwent three stages: constant temperature, insulation heating, and high‐temperature pyrolysis. The insulation layer experiences bulging, exhausting, carbonization, dripping, and burning in sequence, and insulation layer dripping requires at least 160 A of current. As the current increases, the temperature increase rate of the wire increases gradually, and the fusing time of the wire gradually decreases. Under the same current, 160°C is the turning point at which the temperature increases. The temperature increase rate of the copper wire is greater than that of the aluminum alloy wire, and the temperature increase rate of the bare wire is greater than that of the insulated wire. The fusing time of an aluminum alloy wire is less than that of a copper wire, and the fusing time of a bare wire is less than that of an insulated wire. The research results provide theoretical guidance for the prevention and investigation of building electrical fires.

An investigation of the corrosion behavior of zinc-coated stainless steel orthodontic wires: the effect of physical vapor deposition method

BackgroundReleasing of metal ions might implicate in allergic reaction as a negative subsequent of the corrosion of Stainless Steel (SS304) orthodontic wires. The aim of this study was to evaluate the corrosion resistance of zinc-coated (Zn-coated) SS orthodontic wires.MethodsZinc coating was applied on SS wires by PVD method. Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization tests and Tafel analysis methods were used to predict the corrosion behavior of Zn-coated and uncoated SS wires in both neutral and acidic environments.ResultsThe values of Ecorr ,icorr and Rct ,which were the electrochemical corrosion characteristics, reported better corrosion behavior of Zn-coated SS wires against uncoated ones in both artificial saliva and fluoride-containing environments. Experimental results of the Tafel plot analyses were consistent with that of electrochemical impedance spectroscopy analyses for both biological solutions.ConclusionApplying Zn coating on bare SS orthodontic wire by PVD method might increase the corrosion resistance of the underlying stainless-steel substrate.

Fatigue Behavior and Fracture Surface Analysis of Corroded High-Strength Bridge Cable Wires.

Bridge cable wires suffer from alternating stress and environmental erosion, leading to premature failure prior to its design life. This paper investigates the fatigue and mechanical behaviors of corroded bridge cable wires with a zinc-aluminum (Zn-Al) alloy coating. Based on the salt spray corrosion test and microstructure analysis, the anti-corrosion resistance and corrosion appearance characteristics of the Zn-Al alloy coating and galvanized coating were investigated. The Zn-Al alloy coating was superior in resistance to corrosion fatigue for the improvement in toughness and the generation of anti-corrosion Zn-Al and Fe-Zn-Al phases. Equations of the accelerated corrosion depth of the steel wires had been regressed to roughly estimate the corrosion life of the Zn-Al alloy coating, which can reach 29.1 years with a thickness of 70 μm. The fatigue and mechanical properties of the bare wires after the salt spray test were further studied based on tensile tests and fatigue tests. The fatigue properties of the bridge cable wire would decrease with the corrosion degree due to the deterioration and embrittlement of materials, where ductility characterized by the elongation rate was the most affected. Fracture surfaces of the wires were captured and analyzed based on a method for recognizing graphical contours. Insufficient fatigue life may occur in the steel wires after corrosion and increase with the degree of corrosion. The pit depth logarithmically weakened the fatigue life of steel wires for the weakening of fatigue toughness and the bearing area. The flat fracture was more common with a single fatigue source, while multiple fatigue sources led to step-like fractures for the generation of multiple dispersed crack propagation regions. Corrosion fatigue was more sensitive to the existence of fatigue sources than the reduction. Multiple initiation sources significantly reduced the fatigue life due to the cracking facilitation of the joint effect of multiple pits. The electrochemical reactions of corrosion can lead to material embrittlement and a reducing effect on the fracture toughness of the steel wires.

History of cardiac pacemaker therapy in Germany

Cardiac pacemaker therapy began with successful stimulation of human hearts already in the first half of the 20thcentury. Complete implantation of apacemaker by the cardiac surgeon Åke Senning on October 8, 1958 at the Karolinska Hospital in Stockholm is considered the actual birth of today's pacemaker therapy. The first pacemaker implantation in Germany was performed by Hans-Joachim Sykosch on October 6, 1961 at the Surgical Clinic of the University of Düsseldorf. Two years later, the first implantation in East Germany (GDR) was carried out by Friedrich Flemming on September 2, 1963 at the Charité in East Berlin. The first pacemaker manufactured in West Germany arrived on the market 1963; East Germany started device production in 1978. In 1974, pacemaker therapy in West Germany showed a50% survival rate after 6.3years compared to < 1year with drug therapy. After initially using bare metal wires, pacemaker leads have significantly improved in both quality and reliability. Development culminated in the leadless pacemaker. Battery development led to avariety of inventions: rechargeable pacemakers, biogalvanic cells, bioenergy sources, nuclear generators and lithium batteries, the latter ultimately prevailed. In the beginning, only fixed-rate ventricular pacemakers were available. Subsequently, systems adapted to physiological requirements were developed: on-demand pacemakers, atrial-based pacing and rate-adaptive systems. However, it was not until the return to direct stimulation of the conduction system that truly physiological stimulation of the heart became possible.

Beam-Beam Long Range Compensator Mechanical Demonstrator

Beam-Beam Long-Range Compensators employing current-carrying wires are considered as valuable options in hadron colliders to increase dynamic aperture at small crossing angles. This paper presents a simple design proposal for application at CERN LHC. The preliminary design allows for a certain scalability of the number of modules, current flowing in the wire, and dimensions. It complies with two key requirements: (a) the use of a thin, bare metal wire that allows for movement as near to the beam as necessary while minimizing interactions with beam particles and meeting the specified DC current target; and (b) a wire support that is both an electrical insulator and a thermal conductor (ceramic). A molybdenum wire, vacuum brazed on an aluminium nitride support, is proposed, and the design is conceptually proved through the realization and extensive test of a demonstrator device. The wire brazing validation, as well as the system’s heat management, which are the most critical aspects, are given particular regard.

Research on Lightning Overvoltage Protection of Line-Adjacent Pipelines Based on Solid-State Decoupling

Existing transmission lines and pipelines are frequently crossed and erected in parallel, meaning that if lightning strikes a wire and causes insulator flashovers, the resulting lightning current will spread through the grounding of the tower where the flashover insulator is located. This dispersion of current can lead to overvoltage effects on nearby pipelines. This study performs simulation calculations to analyze the overvoltage experienced by pipelines due to the dispersion of grounding current from the tower. Furthermore, this paper proposes a method for protecting the pipeline from such an overvoltage. Firstly, the lightning transient calculation model of a transmission line tower is constructed using the electromagnetic transient software ATP-EMTP 5.5. The model calculates the effects of lightning peak currents and soil resistivity on the distribution characteristics of lightning current in the tower, specifically in the area where the flashover insulator is located. Subsequently, a calculation model of the tower grounding grid–natural gas pipeline is developed, taking into account the distribution characteristics of lightning current in the tower. This model analyzes the impact of lightning peak currents, soil resistivity, and pipeline spacing on pipeline overvoltage. Finally, the effectiveness of the solid-state decoupler in mitigating lightning overvoltage in the pipeline is verified. The results demonstrate a positive correlation between the lightning current entering the tower grounding grid through the flashover insulator and the lightning current distribution characteristics. The solid-state decoupling device proves to be effective in reducing the voltage of the pipeline insulation layer, and the simulation results provide the optimal laying length of the bare copper wire.

Abstract 047: Solumbra ‘PINCHING’ technique for medium vessel occlusions (MeVOs): A Single Center Experience

Introduction Various techniques have been evolved and used by different operators for mechanical thrombectomies for improved procedural performance, lower intraoperative times and better recanalization rates The widely used, isolated stent‐retriever and contact aspiration technique for medium vessel occlusions (MeVOs) carries a high risk for clot fragmentation, spasm and distal migration. The stent–aspiration (Solumbra) technique uses a large bore aspiration catheter with a stent retriever device for potential synergistic effects. However, its use is limited in distal thrombectomies. Hereby, we assess the efficacy and safety of solumbra ‘Pinching’ technique by using a smaller profile aspiration catheter for MeVO thrombectomy. Methods We retrospectively analyzed our prospective institutional database for medium vessel occlusions (M2, M3 MCA/ A2, A3 ACA/ P2 PCA) who underwent endovascular mechanical thrombectomy using stent retriever or aspiration or combined (solumbra) technique. The technique involves deploying a stent retriever through microcatheter and large bore aspiration catheter like ACE 68 (Penumbra, Inc.), followed by both microcatheter and aspiration removal, clot localization and blind navigation of a correctly sized lower profile (3MAX or 4MAX, Penumbra, Inc.) aspiration catheter over stent bare wire to “pinch” the primal end of the clot. Besides various demographic parameters, we collected final recanalization rates with first pass effect [using modified Thrombolysis in Cerebral Infarction (TICI) score]. All the intra‐procedural complications (haemorrhage, vasospasm) were analysed. Clinical outcome was analysed using modified ranking score (mRS) on 7th day post procedure/ discharge(whichever is earlier) and at 90 days. Results Total 26 MeVOs were successfully treated in twenty‐five patients with solumbra ‘Pinching’ technique since January 2022 (Male: female 16:7, mean age 58.6 years, mean NIHSS 9.1). Majority of the procedures were done for primary MeVOs and 72% consisted of M2 MCA occlusions. Whether to use a 3MAX or 4MAX aspiration catheter was determined by eyeballing the appropriate calibre for target vessels. Final first pass mTICI 2c/3 recanalization was achieved in 24 patients (88%). Minor Intra‐procedural complications were observed in 13 patients. Favorable modified ranking score (mRS 0‐2) was achieved in approximately 80% patients at the end of 7 days/discharge and 14 out of 16 follow up patients achieved good clinical outcome at 90 days Conclusion Solumbra ‘Pinching’ technique, using a low profile aspiration catheter like 3 MAX or 4 MAX (Penumbra, Inc.) with a stent retriever, can be effectively used in management of acute ischaemic stroke secondary to a MeVOs with significantly enhancing the first‐pass recanalization with lesser risk of intimal injury, dissection and secondary embolization.

Copper Wire Bonding: A Review.

This paper provides a comprehensive review on copper (Cu) wire bonding. Firstly, it introduces the common types of Cu wire available in the market, including bare Cu wire, coated Cu wire, insulated Cu wire, and alloyed Cu wire. For each type, their characteristics and application areas are discussed. Additionally, we provide detailed insights into the impact of Free Air Ball (FAB) morphology on bonding reliability, including its effect on bond strength and formation mechanisms. Next, the reliability of Cu wire bonding is analyzed, with a focus on the impact of intermetallic compounds and corrosion on bonding reliability. Specifically, the formation, growth, and stability of intermetallic compounds at bonding interfaces are discussed, and their effects on bonding strength and reliability are evaluated. The detrimental mechanisms of corrosion on Cu wire bonding and corrosion inhibition methods are also analyzed. Subsequently, the applications of simulation in Cu wire bonding are presented, including finite element analysis and molecular dynamics simulations, which provide important tools for a deeper understanding of the bonding process and failure mechanisms. Finally, the current development status of Cu wire bonding is summarized, and future research directions are discussed.

Magnetization Loss and Current Transport Characteristics of SCSC Cables With Metal Cores

The SCSC cable is a low-ac-loss, robust, and high-current cable concept, in which copper-plated multifilament coated conductors are wound spirally on a core. Its copper connecting filaments electrically improves the robustness against local defect and local normal transition. Its spirally geometry plays an equivalent role to the twist geometry of low <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> superconductors in order to decouple filaments and, then, to reduce magnetization losses effectively. We fabricated four-layer SCSC cables with metal cores, which are preferable from the viewpoint of current sharing to help quench protection, but in which eddy current loss might be generated under ac magnetic fields. In order to examine the influence of metal cores on the magnetization losses, we measured the magnetization losses in SCSC cables, whose cores were twisted copper wires (twisted bundle of copper wires) and a GFRP rod, as well as those in various cores themselves. We fabricated four-layer SCSC cables whose core was twisted bare copper wires, and examined its current transport characteristics in liquid nitrogen.

Insulated, Passivated &amp; Adhesively-Promoted Bond Wire Using All-in-One Al2O3 Coating

Insulated, Passivated &amp; Adhesively-Promoted Bond Wire Using All-in-One Al2O3 Coating

Preparation of Polyurethane-Modified Silicone Rubber Insulating Coating and Its Application in 10 kV Overhead Bare Wire Wrapping

Room-temperature vulcanized rubber is an excellent polymer material with excellent electrical insulation and mechanical properties, which can be used for field insulation of high-voltage bare wire. In this paper, a room-temperature cured coating material was prepared from α,ω-dihydroxy polydimethylsiloxane (PDMS), polyurethane-modified silicone material (PU-Si), and Methyltris(methylethylketoxime) silane (MOS). The study showed that the coating made by adding PDMS (70 g), PU-Si (30 g), CaCO3 (90 g), MOS (7 g), KH792 (5 g), and Mg(OH)2 (30 g) had a surface drying time of 19.1 min, tensile strength of 3.2 Mpa, volume resistivity greater than 4 × 1014 Ω·cm, breakdown voltage greater than 20 kV/mm, and flame retardant performance of the FV-1 level. The comprehensive performance of the insulation material meets the national standard of “Aerial insulated cables for rated voltage of 10 kV” (GB/T14049-2008), while the insulation material has been successfully applied to the overhead line renovation project of the State Grid Hubei Electric Power Company (Wuhan, China).

Enhanced fog collection of hydrogel-coated wires inspired by water film-trapping characteristics of Tillandsia

Fog collection has been widely studied to collect fresh water in arid regions. With the demand of optimizing the design of fog collectors, removing the pinned droplets and accelerating the water drainage have become a challenge. To address this challenge, we propose a fog collection method utilizing calcium alginate hydrogel-coated wires inspired by the water film-trapping characteristics of Tillandsia. Maintaining the effective wire diameter by water film trapped on the hydrogel, the fog collection performance of our hydrogel-coated wire precedes that of a bare wire in collection efficiency (up to 136 % higher) under different flow speed conditions. Significantly, retaining the inter-distance between dual-wires, the collection efficiency of hydrogel-coated dual-wires is 1.2 ∼ 1.7 times higher than that of two bare dual-wires. Moreover, the hydrogel-coated wires prevent the formation of water bridges between wires by removing the deposited droplets promptly, which opens different perspectives on designing the hydrogel-coated wires for the purpose of water harvesting, sustainable engineering, and ecofriendly technology.

Robust extruded tungsten tellurite glass fiber with excellent mechanical properties for infrared applications

Robust tungsten tellurite (70TZLW) glass fiber consisting of 70TeO2-16ZnO-4La2O3-10WO3 core and 70TeO2-16ZnO-5.5La2O3-8.5WO3 cladding (in mol.%) was prepared by extrusion method. Due to the adding of La2O3 and WO3, 70TZLW glass exhibits higher glass transition temperature (385–395 °C) and thermal stability (>145 °C) than those of TeO2-ZnO-Na2O glasses, which is beneficial to the drawing of optical fiber. In addition, the mean optical losses of the bare wires drawn by the core and cladding glass preform are about 1.19 dB/m and 1.16 dB/m, while that is about 1.04 dB/m for the fiber drawn from the accordingly extruded preform at the wavelength of 1310 nm. Moreover, the average mechanical bending strength of the fiber reaches to about 570 MPa with a Weibull slope of 67.4. These results show the improvement in work ability and the greater practical potential of the 70TZLW extruded fiber compared to TeO2-ZnO-Na2O fibers for infrared application.

Птицезащитные устройства для воздушных ЛЭП и подстанций – проблемы мониторинга и оценки эффективности птицезащитных мероприятий

Птицезащитные устройства для воздушных ЛЭП и подстанций – проблемы мониторинга и оценки эффективности птицезащитных мероприятий

Morphology and Electrochemistry Drive Corrosion of Electroless Nickel Immersion Gold Films: A Multi-Technique Analysis

Electroless nickel immersion gold (ENIG) is a common surface finish for high-reliability microelectronics circuitry due to its good solderability, corrosion resistance, layer thickness uniformity and applicability for fine pitch applications1. ENIG deposition is a multistep process in which a 3 to 6 micron (118-236 μ-in) layer of electroless nickel (i.e. Ni-P) is deposited onto the substrate material (typically copper), followed by a galvanic displacement reaction replacing the surface layer of Ni with 0.04 to 0.1 microns (1.6 to 4 μ-in) of gold (Au). Despite ENIG’s widespread use, it continues to suffer from a failure mode known as “black pad” or Ni hypercorrosion during immersion gold deposition2. A cohesive mechanistic explanation for the occurrence of Ni hypercorrosion is not yet established despite extensive study. Recent approaches have attempted to characterize in-situ the influence of bath chemistry; however, the competing influence of all variables of the ENIG process (e.g. temperature, pH, solution chemistry, volume mixing, surface morphology, etc.) make global mechanistic conclusions challenging if not impossible experimentally3. Instead, the work here aims to develop tools to assess an ENIG film of unknown origin or deposition conditions for the risk of corrosion. Therefore, this study utilizes a combination of surface characterization via x-ray photoelectron spectroscopy (XPS) depth profiling and transmission electron microscopy (TEM) imaging and electrochemical characterization via cyclic polarization (CP) and scanning vibrating electrode technique (SVET) to build a multi-technique analysis of ENIG failures.ENIG samples with identical geometries and plating requirements from two domestic vendors (A & B) were obtained. XPS with argon ion sputtering allows for comparison of atomic concentration of Ni, Au and P in ENIG films through their depth as a function of the number of sputter cycles. XPS results show that Vendor A films have a high concentration of Ni in the Au layer and a lower concentration of P near the Au-Ni interface, whereas Vendor B films have a low concentration of Ni in the Au layer and a higher concentration of P near the Au-Ni interface. This indicates a more porous morphology in Vendor A versus B films. SVET is an electrochemical scanning probe tool which allows for real-time observation of cathodic and anodic currents (in a 0.35% NaCl solution) representing existing and developing defect sites on ENIG surfaces. SVET experiments show that Vendor A and B samples exhibit preferential anodic currents on ENIG surfaces corresponding to Ni hypercorrosion defects. Focused ion beam (FIB) lift-outs from SVET samples viewed in TEM give ex-situ confirmation that SVET observations align with the real metal layer structure and chemistry as well as confirming the presence and location of corrosion products. CP curves for samples of each film in a 0.35% NaCl solution demonstrate that both Vendor A and Vendor B films exhibit effective corrosion rates above 1.0 mil per year which is on the order of bare Cu wire in the same electrolyte. Overall, a distinct difference in film morphology between Vendor A and B samples exists; however, both films exhibit substantial electrochemical activity in solution indicating corrosion susceptibility. Taken together, these results show that Ni hypercorrosion can be driven by at least two distinct mechanisms: high porosity in the Au film leading to enhanced Ni migration and reaction at the Au surface; or, P enrichment at the Au-Ni interface leading to enhanced P migration and a more electronegative surface composition. Future work will build out characterization of additional ENIG samples to establish a failure matrix for ENIG films, encompassing a wider variety of unique mechanisms. D. Goyal, T. Lane, P. Kinzie, C. Panichas, K. M. Chong, and O. Villalobos, in "52nd Electronic Components and Technology Conference 2002.(Cat. No. 02CH37345)", p. 732-739. IEEE, 2002.R. Ramanauskas, A. Selskis, J. Juodkazyte, and V. Jasulaitiene, Circuit World, (2013).A. Accogli, E. Gibertini, G. Panzeri, A. Lucotti, and L. Magagnin, Journal of The Electrochemical Society, 167 (8), 082507 (2020). SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525

Leveraging Solidification Dynamics to Design Robust Ice-Shedding Surfaces.

The adhesion of ice to external surfaces is an important challenge in many industries. This has sparked much research into fabricating surfaces with low ice adhesion strengths. Our novel approach to designing ice-shedding surfaces leverages the dynamics of water solidification to induce beneficial stress concentrations throughout the iced interface. We have chosen a bare woven metal wire cloth substrate to demonstrate these principles. The pore geometries of the wire cloths lead to stress concentrations upon freezing and expansion of the water/ice, while their microstructural topography allows for facile crack opening. We have discovered that by leveraging knowledge of the underlying physical processes involved in ice formation and delamination, we can engineer a robust metal surface to have an extremely low ice adhesion strength (12.5 kPa) without using chemical coatings.

Morphological and Electrical Properties of Polythiophene Nanostructured Film Synthesized Using Atmospheric Pressure-Plasma Reactor with Double V-Shaped Bare Electrode

To synthesize a wide-area conducting polymer with improved morphology and electrical properties, we proposed a new atmospheric pressure (AP) plasma reactor with double V-shaped bare wire electrode operating at a low driven voltage to expand the plasma area for nanostructure synthesis. The two wires form a V-shape making a 60° angle at the edges and are joined together forming a cross, creating a canopy-like plasma medium in the plasma reactor center. Using the AP-plasma reactor, the polythiophene (PTh) nanostructured films are successfully synthesized with and without iodine doping. Moreover, the molecular structures and chemical properties of nascent and iodine-doped PTh films are compared, and the electrical resistivities of ex situ and in situ iodine-doped PTh nanostructures are also analyzed.