The revolution in mobile devices came from the hands of the touchscreens, but this essential component of smartphones and tablets is subject to the scarcity of a material essential to their manufacture: Indian, one of the rarest minerals in the world. Fortunately, a group of researchers has developed an alternative technology to form the material for making touchscreens that is now an essential element in the handling of electronic devices, although there are alternative technologies that eliminate the need to physically touch the surface.
A “plasma soup” enables the development of an alternative material for the production of touchscreens
As published in the Solar Energy Materials and Solar Cells Journal, a group of researchers from the School of Biomechanical Engineering and the School of Physics at the University of Sydney (Australia) succeeded in an alternative technology to the Indian one to continue making touchscreens without using this rare mineral. For this purpose, a new method was developed, based on a “Plasma Soup”.
Indium oxide is a crucial material for high-tech devices such as touchscreens or solar modules, products that have been in high demand in recent years but are dependent on the scarcity of indium, a material that practically cannot be extracted directly from the earth and that you have to search for tiny traces mixed with other materials, mostly between zinc, also depends on the demand for this other mineral.
Recycling indium is also not very practical because of the small amounts of this material in cell phones and the high cost and complexity of its recovery and reuse.
The newly developed process is based on a plasma-based connection in which two layers of tungsten oxide surround an extremely thin layer of silver. It’s a structure of hardly 100 nanometers thick, one thousandth the thickness of a human hair.
This “sandwich” is immersed in a mixture of argon and oxygen gases that are exposed to a strong electric field until they turn into plasma (the fourth state of matter), which is bombarded at a solid piece of tungsten, from which they emit atoms, they are deposited in a thin layer on a glass surface. The process is repeated with later silver and finally a final layer of tungsten oxide embedded with silver nanoparticles.
The result is achieved in minutes, with minimal waste and at a much lower cost than using indium, which can be used make every glass surface tactile, both from a mobile device and from a window.
In addition, this glass layer with haptic properties has a very special property: it’s electrochromic, which means that its opacity index can vary depending on the electrical charge absorbed. This opens up an unprecedented field of possibilities in that color-changing screens can be produced with very little energy.
It can also be used to darken windows so that they filter the sunlight and thus regulate the temperature.