21 Jun 2019

Indium - Queen of the touchscreen

From Elemental, 8:00 am on 21 June 2019

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.

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Photo: 123RF

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The Elemental podcast is celebrating 150 years since the periodic table was first published by Russian chemist Dmitri Mendeleev.

Find out more about events during the United Nation’s International Year of the Periodic Table.

Nights with Bryan Crump is also celebrating the chemical elements during their Friday night Sonic Tonic and Element of the Week.

Professor Allan Blackman is at Auckland University of Technology.

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Photo: RNZ