"Our copper wire manufacturing technologies, which originated from Sumitomo’s copper business, were subsequently applied to electrical wire and cable products. Based on these products, the Sumitomo Electric Group has continuously developed its new technologies and products. Electrical wire and cable manufacturing technologies are divided roughly into conductor technologies and covering material technologies required for insulating wires. Let us take a look at the history of diversification of Sumitomo Electric’s products along with the growth of these technologies."

As part of its overseas business, Sumitomo Electric Industries, Ltd. has been providing contact wires for the high-speed dedicated freight corridor that is being constructed in India. To enter the Indian contact wire market, it was necessary to satisfy the specifications required by the local customer, such as high conductivity and high tensile strength based on overseas standards. Taking advantage of our accumulated expertise in copper-tin alloys, we achieved the required properties by adjusting the tin and oxygen ratio in material casting and by improving the drawing process of contact wire. This paper introduces our technical development.

The air spring is an essential component for improving the comfort of railway vehicles and realizing safe high-speed driving. Due to the growing urban population and increased concern about environmental issues, railways are attracting attention because they have higher transportation efficiency than automobiles and aircraft and contribute to the reduction of CO2 emissions and energy consumption. As the railway network spreads all over the world, air springs with various characteristics are required depending on the route and environment. To respond to such market needs and make proposals in a speedy manner, we are developing innovative design methods based on computer simulation. This time, we have developed a simulation technology that accurately predicts the static and dynamic characteristics of air springs.

The electrification of vehicles has been advanced rapidly with the aim of reducing environmental impact. This paper summarizes the transition of motor design technology and its future development trends with a focus on driving motors for electric vehicles as a benchmark. We also report on the current status of our efforts towards the development of rectangular wires that contribute to the improvement of motor performance. In our efforts, we have worked to enhance the insulation performance of the film coating for magnet wires and reduce their size variation.

Magnet wire is an electrical wire coated with an insulation film. We analyze its constituent elements such as a conductor, insulation film, and the interface between them, in order to improve the quality and performance of the wire. It is increasingly important to develop novel and advanced analysis technologies and use them depending on the purposes of analysis. This paper reports on our unique technology and approach to the analysis of the aforementioned elements.

With the spread of mobile devices, market needs are increasing for the improved sound quality of small speakers. Self-bonding magnet wires used in the voice coils of small speakers are required to be durable against vibration and to be lightweight for enhanced responsiveness in a high-frequency range. Our copper-clad aluminum wire is resistant to fatigue fracture caused by vibration. The wire comes with various densities and conductivities by changing the composition ratio of the copper coat and aluminum core. This paper reports on the development of the wire that has increased flexibility in coil design and durability for the improved sound quality of small speakers.

The composite metal wire is composed of multiple metallic phases and has multiple functions at a relatively low cost. The Sumitomo Electric Group offers a variety of composite metal wire products that are made by cladding and plating. This paper introduces the technologies and application examples of our wires.

Celmet, the unique porous metal product of Sumitomo Electronic Toyama Co. Ltd., has high gas-diffusivity and high electric conductivity. Celmet is a good candidate for the cathode current collectors of solid oxide fuel cells (SOFCs) that require uniform gas-diffusivity and high electric conductivity. Thus far, we have examined the application of nickel (Ni) Celmet to the collectors, however, the desired output power density has not been obtained due to the decrease in electric conductivity caused by the oxidation of Ni at high temperature of the fuel cells. We have developed new nickel cobalt (NiCo) Celmet that forms conductive ceramics, keeping high electric conductivity at high temperature and highly oxidizing atmosphere. This paper introduces the physical properties of the NiCo Celmet and reports on the performance of an SOFC that uses the new Celmet for its cathodic current collector.

Heat shrinkable tubing is used for the insulation and mechanical protection of electric wires in fields such as electronics and aircrafts. Among such tubing, dual-wall heat-shrinkable tubing is used for the waterproofing of automotive wiring harnesses at the joints of electric wires. In recent years, with the aim of improving fuel efficiency and reducing vehicle weight for the reduction of CO2 emissions, aluminum wires have been attracting attention as the replacement of conventional copper wires. We have developed a new dual-wall heat-shrinkable tubing for the anti-corrosion protection of aluminum wires at their terminals.

Fluororesin, represented by polytetrafluoroethylene (PTFE), is an excellent polymer that has the lowest level of friction performance among solids and the highest level of heat resistance, chemical resistance, weather resistance, and electrical properties among resins. In contrast, it has poor wear resistance and hardly adheres to substrates when used as a composite material. Through electron beam irradiation under special conditions, we promoted the cross-linking reaction of fluororesin and developed a new material that features wear resistance improved nearly 1,000 times compared with the conventional material and good adhesion to substrates. This paper investigates the cross-linking state of the new material using solid-state nuclear magnetic resonance, and elucidates its adhesion state to substrates utilizing SPring-8 hard X-rays.

We have applied cross-linking technology to plastic materials through high-energy electron-beam irradiation to obtain gears with high durability. Sumitomo Electric Fine Polymer’s Teralink cross-linked gears, which use polyamide 66 as their base polymer, exhibit a three-fold improvement in durability in terms of the amount of tooth load that they can withstand compared to gears made of the same base polymer.

Porous polytetrafluoroethylene (PTFE) membranes were first developed by Sumitomo Electric Industries, Ltd. as “POREFLON.” Thanks to its high chemical and heat resistance, POREFLON has been used for microfiltration in various industrial applications. With advanced technological innovations, Sumitomo Electric has newly developed a nano-porous PTFE membrane “POREFLON NANO” and confirmed its high degassing and gas separation performance.

We have developed and marketed a new POREFLON membrane module unit for water treatment. It has a smaller footprint and is more energy saving than conventional products. In addition to the features of the conventional POREFLON hollow fiber membrane such as fouling resistance, high strength, and bending resistance, the module unit features the cassette type module structure, increased effective membrane length, enhanced packing density, and newly developed air diffusers that generate large air bubbles to prevent fouling. In a pilot test for municipal wastewater treatment jointly conducted with Japan Sewage Works Agency and others, we achieved a power consumption per unit of 0.4 kWh/m3 or lower, which was the target point for the popularization of membrane treatment. The module unit passed another several field trials and was currently commercialized. This report introduces the development process, product specifications, and case studies regarding the new membrane module unit.

Sumitomo Electric Industries, Ltd. has developed an Ethernet access switch for Carrier Ethernet that contributes to the reduction of operation expenditures. We have integrated functions of a fiber optic media converter and a layer-2 aggregator into one Ethernet access switch. This has enabled a power- and space-saving solution compared with conventional device sets. The switch features hitless firmware upgrades, zero touch provisioning, NETCONF, alarm notifications and line test capabilities. At the end of the paper, we report on the experimental results of Streaming Telemetry.

This paper reviews device design and performance of high-speed vertical cavity surface emitting laser (VCSEL) arrays for nextgeneration short-reach 400 Gbit/s applications in data centers using the advanced PAM-4 modulation format. The both 850 nm/900 nm PAM-4 VCSELs have been optimized to improve dynamic performance and suppress noise for PAM-4 transmission. The new VCSELs also show good uniformity of characteristics, which is advantageous for array products.

Demand for high-resolution displays and virtual reality applications is increasing and the use of these devices is spreading rapidly in the consumer electronics market. Cables attached to these devices are required to support high-speed and long-distance transmission, while maintaining their plug size. We have developed an active optical cable with a USB Type-C connecter (a smallsized multifunctional interface) and a plug of the same size as that of a conventional cable. This paper introduces the new cable, describing its design, transmission characteristics, and results in a reliability test.

In the machining industry, long tool life and high machining efficiency are required for cost reduction and productivity improvement, and sudden troubles need to be reduced for factory automation. Furthermore, machining facilities have been increasingly integrated into single facilities that can process various work materials. In such circumstances, we have developed a general-purpose grade “ACU2500” that achieves a stable and long tool life in the milling of a wide range of work materials including steel and cast iron. We have also developed special grades ”ACP2000 / ACP3000” and “ACK2000 / ACK3000” that offer high machining efficiency and long tool life in steel milling and cast iron milling, respectively. While covering a wide variety of work materials, these five grades demonstrate 1.5 times longer tool life and twice higher efficiency than conventional grades, enabling significant cost reduction and productivity improvement.

Cermet tools, characterized by low affinity with steel, realize high-quality finished surfaces in steel cutting and are commonly used for finishing. In the automobile, industrial machinery, and other manufacturing industries, high machining efficiency has become important year by year for lessening the environmental impact and machining costs. In increasingly severe machining conditions resulting from the pursuit of high efficiency, cermet tools are strongly required to offer long tool life and high-quality finished surfaces. Under such circumstances, we have developed and launched “T2500Z,” a new cermet grade that features a long tool life and excellent finished surface quality. The T2500Z has twice the tool life of our conventional steel-turning grades, thus making it possible to meet user needs for high efficiency.

Thermoelectric generation that directly converts waste heat into useful electric power has attracted considerable attention as one of the most efficient techniques leading to a low carbon, sustainable society. For automobile exhaust heat power generation, the figure of merit (ZT) of thermoelectric materials, which parameterizes the efficiency of energy conversion, needs to be more than 4, but at present it is considered to be extremely difficult to reach. We are conducting research and development to overcome this issue by modulating the electronic structure of materials, that is, with precise control of nanostructures. By controlling nanostructures, we have succeeded in lowering the thermal conductivity of conventional Si-Ge thermoelectric materials to 1/7 and improved their materials figure of merit. In this study, in order to improve the performance even further, we propose a unique technique called a co-doping method (modulating electronic structures with doped Au and controlling the Fermi level with doped B). With this method, we have achieved ZT = 1.38, which is the best result for the same materials of the same type.

A quantum cascade laser (QCL) is the most promising semiconductor laser for trace gas sensing in the mid-infrared region due to its excellent features such as a small chip size, high speed modulation, and a narrow linewidth. In practical gas-sensing, QCLs are required to achieve single-mode operation and wide-wavelength tuning without mode-hopping for high-sensitive and multiple gas detection. To obtain the wide tuning range of QCLs, increasing the operation temperature is effective. Therefore, we have developed a distributed feedback (DFB)-QCL that can operate at high temperature by introducing our original strain-compensated core structure and buried-hetero waveguide structure. As a result, we have successfully achieved single-mode operation without mode-hopping between -40ºC and 200ºC under a pulse condition, leading to a wide tuning range of 123 nm with only a singlewaveguide QCL. As a future challenge, we will develop a gas-sensing method using the above-mentioned DFB-QCLs as the light source.

In recent years in Japan, behind the widespread use of cloud computing, data center networks serving as a fundamental technology have been handling an increasing amount of data transmission, which also lead to a growing for increased ultra-high-fiber-count and higher-density cables. Sumitomo Electric Industries, Ltd. has successfully commercialized the world’s first cable containing 3456 or more fibers and shipped it to its many customers.

"With the recent expansion of cloud services, countries around the world are facing a pressing need for building data centers. Optical fiber cables for data center applications now comprise of thousands of core optical fibers. There is a noticeable tendency for these cables to be made even denser by increasing the number of core optical fiber cores, for example, from 1728 to 3456. As optical fiber cables become increasingly dense, data center construction companies have high expectation for a device that improves work efficiency through mass fusion splicing of ribbon fibers. To meet these users’ new expectations, Sumitomo Electric Industries, Ltd. has developed a new ribbon fiber splicer TYPE-72M12 that both saves optical fiber splicing/heating time and reduces workloads."