British scientists have broken the record for the world’s tiniest Christmas card – and it’s 200 million times smaller than a postage stamp.
The card, which is 15 micrometres by 20 micrometres, even includes an intricate inscription of a snowman and seasonal messages – despite being too small to see with the naked eye.
It was created by scientists at the National Physical Laboratory in Teddington, south west London, who say it is 10 times smaller than the previous record holder.
A micrometre is the equivalent to one millionth of a metre.
British scientists have broken the record for the world’s smallest Christmas card – and it’s 200 million times smaller than a postage stamp. The tiny card is pictured with its snowman design
It was created by scientists at the National Physical Laboratory in Teddington, south west London, who say it is 10 times smaller than the previous record holder
The card, made on a silicon nitride membrane has a coating of super-expensive platinum, which is worth 0.000002p.
Dr David Cox, Research Fellow at NPL, created the card with colleague Dr Ken Mingard.
Dr Cox said: ‘While the card is a fun way to mark the festive season, it also showcases the progress being made in materials research on this scale.
‘We are using the tools that created the card to accurately measure the thickness of extremely small features in materials, helping to unlock new battery and semiconductor technologies.
‘It’s a genuinely exciting development that could help to make new technologies and techniques a reality.’
The card is so tiny, about seven quadrillion of them could fit into an average post box – which is 900,000 cards for every person on earth.
A microscope image of a human hair magnified 2,000 times shows the tiny scale of the card
Dr Cox added: ‘When we want to investigate the 3D structure of materials we can do this by cutting it away in slices with a focused ion beam.
‘The slices may be 20 times thinner than the card shown on the front but it is very difficult to measure precisely how thin.
‘Variation and errors in how thin the slices are can lead to false impressions of the true 3D structure.
‘To determine each slice thickness, a disposable ‘ruler’ can be put down on top of the sample so that it is cut away at the same time as the material below.
‘The amount of ruler milled away can be measured accurately and thus the thickness of the slices determined.
‘The disposable rulers are made on the same material and with the same technology used for the card, and it was during making of the rulers that we realised we could make a card which folded itself very quickly and easily.’