In our search for new metamaterials we have arrived at the delirium: one capable of counting to ten

In the long, fast-paced and often fascinating race to develop new materials, a group of physicists in the Netherlands have just achieved a surprising result: a metamaterial. able to count to ten. And even remember the order in which it is pressed. Those responsible have already described the details of the work in the journal ‘Physical Review Letters’ and recorded a video that shows the surprising properties of his creation, just as if it were a peculiar sleight of hand trick. All they need is a small block.

Now they are thinking about possible applications.

A metamaterial capable of counting? True, it sounds crazy, but that is what ensures the Leiden University, in the Netherlands. There, Professor Martin van Hecke and PhD student Lennard Kwakernaak, authors of an article recently published in the magazine ‘Physical Review Letters’ in which they explain how they have created a block of rubber endowed with amazing properties. The piece, with flexible sheets, is a sample of a mechanical metamaterial capable of counting and remembering the order in which it receives pressure.

What exactly have they presented? “Irreversible metamaterials that count mechanical conduction cycles and store the result in easily interpretable internal states.” This is how they present it in your article. The explanation may be a bit dry, but it is much better understood when you see demo video that Lennard Kwakernaak himself has engraved with a small rubber block made up of 22 flexible beams grouped in pairs.

When the block is pressed all the bars bend to the left. All except the first, which turns to the right. If you repeat the process something similar happens, although the number of sheets that are oriented to the right increases. Each one that has turned to that side shows a mark that helps identify how many times the block has been pressed. “That first bar pushes the next couple to the right and moves one position each time the material is pushed. That’s how it counts to ten,” explains the researcher from Leiden.

What is that metamaterial? The concept is not new. By metamaterial It is understood those materials structured artificially and with unusual properties, which are not easily found in nature. His research has been particularly fruitful throughout the last two decades and in Xataka we have already told you about some capable of acting as “acoustic glasses”absorb vibrations without sacrificing rigidity or can even move without the slightest contact, using only their response to sound waves.

To be more precise, the block of rubber that they have shown at the University of Leiden is a mechanical metamaterial, a label that is assigned to those materials that have properties that are influenced by both their composition and their structure. One of its great advantages, claims Kwakernaak, is that creations like the one he proposes are relatively cheap, robust and require little low maintenance. “It makes them interesting for all sorts of applications.”

And what applications will it have? “It’s hard to say what they will be, but we always find a use for new materials like this. Previous research on a material that folds like origami inspired the folding of solar panels on a satellite,” notes Kwakernaak. From the University of Leiden they remember after all that a bar capable of adjusting from left to right can be compared to a computer bit and they slip possible future uses, such as counting vehicles of different classes or in pedometers.

The possibilities of the metamaterial go beyond the ability to record pressures. The researcher assures that in a certain way he can also discern them. “I discovered that you can cause different reactions in the rubber by pushing with different levels of force —Add—. By experimenting with this, I managed to make a metamaterial that only counts to the end if pushed in the right order, with the right amount of force. A kind of lock, in other words.”

And now that? The researcher wants to go further and devise an even more complex structure, with bar interactions that do not go in just one direction, but in a plane. “That would actually be a simple computer,” Kwakernaak slips. It won’t be easy. “How exactly such a thin beam is bent is much more complicated than it seems. A computer can barely simulate it,” comment.

“Our metamaterials are robust, scalable, and extensible, enabling a better understanding of transient memories in complex media, and opening new avenues toward intelligent sensing, soft robotics, and mechanical information processing,” emphasizes the study which have just been published.

Images: University of Leiden

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