Japanese scientists have developed a technique to transform a copper-based substance into a material that imitates precious and expensive metal properties, such as gold and silver. The new medium, made from copper nanoparticles (very small copper-based structures), has promising applications in the production of electronic devices that would otherwise depend on expensive gold and silver counterparts. It is also suitable in the manufacture of electronic components using printing technologies that are recognized as ecologically correct production methods.
The study was published on January 29 Scientific Reports, an open access journal managed by Nature.
The development of the Internet of Things (IoT) has rapidly increased demand for thin, wearable electronic devices. For example, IoT depends on communication between the devices, which requires antennas that up to now have required expensive metal compounds based on gold and silver.
To date, existing techniques for the preparation of copper nanoparticles have not been ideal as they have resulted in impurities bound to the material. Because these impurities could only be removed by extremely high temperatures, the copper nanoparticles that were created at room temperature were impure and therefore could not solidify into usable parts. So far, this has been one of the obstacles to creating a more economical alternative to gold and silver parts in electronic devices.
The joint study between researchers at Tohoku University and Mitsui Mining & Smelting Co., Ltd in Tokyo reports the successful synthesis of copper nanoparticles with the ability to solidify at much lower temperatures while remaining pure. The team has altered the structure of copper nanoparticles and made them more stable so they do not degrade at low temperatures.
"Copper has been an attractive alternative material in the preparation of electrical circuits. The most important part of using copper is to change it so that it solidifies at low temperatures. So far, this has been difficult because copper interacts readily with moisture in the air and degrades, which turns into unstable nanoparticles. With the methods used in this study that alter the carbon structure and thus make it more stable, we successfully overcome this instability problem, "adds Kiyoshi Kanie, Ph.D., associate professor at the Institute for Multidisciplinary Research Advanced Materials. of Tohoku University.
Researchers hope to expand the application of their copper-based nanoparticles beyond electronics. They believe that this material will be useful in other industries as well. "Our method has effectively created materials based on copper nanoparticles that can be used in a variety of flexible, wearable on-demand devices that can be manufactured easily through printing processes at a very low cost," adds Kanie.