Researchers have created a way to make any mineral surface tactile. It is easy to use. It offers amazing photochromic properties. And, most importantly, it does not use indium, a rare and expensive metal, currently used in smartphones and tablets.
The smartphone has become such an important product in everyday life that it is difficult to do without it. And our connectivity needs are changing very quickly. So much so that we regularly change our smartphones. Several hundred million smartphones are sold each year. You know, in smartphones some rare materials are used . And the sustainability of some of them is called into question. This is the case, for example, with indium .
Indium, we talk about it regularly in our columns. It is a metal that is used to produce the capacitive layer of smartphone touch screens. It is transparent and conductive. Indium is used for touch screens of all sizes (smartphone, watch, tablet, car dashboard, etc.), as well as on certain glazing and solar panels. There are no indium mines. It must be flushed out (often in zinc mines). It is therefore expensive. And the risk of out of stock has been raised by researchers for several years.
THIS NEW COATING TRANSFORMS GLASS INTO A TACTILE SURFACE
Researchers at the University of Sydney have presented some very interesting work to try to replace indium. They use two less rare metals: tungsten (and more precisely tungsten oxide) and silver . Through a process using plasma (formed from argon and oxygen), they created a method to deposit a transparent and conductive coating on glass. And it only lasts a few minutes.
This coating consists of three layers: a first of tungsten oxide, a second of silver and a last (the one in contact with the fingers) of tungsten oxide pockmarked with silver particles. Note that money is particularly conductive: it is money that transmits information. This technique is industrially less expensive than that involving indium. And it works equally well with flexible or solid glass. In addition, the coating is very thin: 100 nanometers thick (one thousandth of a hair).
ELECTROCHROMISM: THE SECOND KISS COOL EFFECT
As an incredible side effect, the tungsten and silver coating is electrochromic: it is sensitive to changes in electrical voltage. If you change the voltage, it changes color and becomes more or less opaque . This would allow, for example, a traditional window to become smarter by changing color as needed. Even change color on a well-defined surface to display information, for example. This technology could therefore replace, for example, the liquid crystals used in electronic books.