Indium - Queen of the touchscreen

Indium is a very soft metal, and as indium-tin-oxide it is an indispensable part of the swipeability of touchscreens, says Allan Blackman from AUT in ep 38 of Elemental.

If you use any kind of touch screen, whether smart phone or tablet, you have the element indium to thank.

ITO is indium oxide with a tiny amount of added tin. ITO conducts electricity, thanks to the tin, and it is transparent to visible light. These two features make it the perfect addition to the toughened glass screen of capacitive touch screens.

When you press your finger against the touch screen, an invisible grid of indium tin oxide senses the electrical disruption and this indicates where on the screen you have touched. It also enables you to swipe and pinch.

ITO won't be so useful in future, as it doesn't work with flexible touch screens.

Indium is also used in solar cells, says Professor Allan Blackman from AUT.

Go to this episode on rnz.co.nz for more details