Rebelious Metamaterial


Researchers in Northern University in Evanston, Illinois, have created a new type of metamaterial with an outstanding quality: negative compressibility, which means the material compresses when stretched and expands when pushed.

For those who don’t know, a metamaterial is a synthetic material with a special structure that allows it to have different characteristics to those of natural materials.

This is not the first time a metamaterial with these properties has been built, but it’s the most successful one. Previous attempts to form this stable metamaterial have been carried out, but they had to have very specific vibrations, whilst this new type just needs a steady force.

To make such a unique material, scientists have created a design to make such special characteristics take place.

It consists of s row of 4 particles with attraction between each other. The two inner particles have a weak attraction force, so any slight force (like pulling the material) breaks the bond. But when this happens, the outer particles attract more to each other, so the material actually compresses.

Vice versa, if the material is squeezed the two inner particles create another bond, repel, and cause the material to expand

This type of metamaterial has many uses, which could go from making cushions that expand when you sit on them to protective cats on military vehicles, so if a something hit the car or tank, the metamaterial will push it back and reduce some of the effect.

However, this material is not the only famous metamaterial that has been made. A few months ago, scientists developed the so called ‘invisibility cloak’, made of silver nanowires in porous aluminium oxide, which could deviate light rays and make objects behind the material invisible.

But, what both have in common, is that the general population won’t be able to buy them, as they still need to be improved and will only be used for the government and the army.

If you haven’t understood quite clearly the internal model of this material, you can see the diagram created by Zachary Nicolau and Adilson Motter (the designers of this material):

 

Source Used:

http://www.newscientist.com/article/dn21839-impossible-material-would-stretch-when-compressed.html

A Robotic Dream


Finally, an era where robots can help disabled people to fulfil their dreams has arrived.

This incredible news come from Brown University in Providence, Rhode Island, USA, where, thanks to an aspirin sized set of electrodes implanted in her brain, the amazing 58 year old Cathy Hutchinson with a stroke that paralysed most of her brain and lost her use of the limbs, was able to drink alone again.

The experiment consisted in implanting a small device in the person’s motor cortex (which is the part of the brain that controls movement in the body) and connect this to some computers. These computers were able to receive the patient’s neurological signals, match them to their corresponding movement order, and send this information to other computers which accomplished all the tasks.

One of the tests was to make the two other volunteers (the woman and a 66 year old man) reach out, with the robotic arm, a foam sphere, and grab it. The results were really good: one of them got the ball in 46% of all the attempts and the other a 62%.

Another test, the most famous one as it demonstrated how this new project can help our society, was the experiment in which the woman took part. The robot arm was supposed to move according to the Hutchinson’s orders, and grab a cup of coffee, move it to her mouth so she could drink from the straw, and leave it back in the table again.

For this, the scientists told her to imagine she was moving the robot arm, which caused neuronal signals the computers were able to detect and transform into orders the robot arm carried out.

The inventor of BrainGate, the technology used in this experiment, John Donoghue, explains how happy the woman was after completing the experiment and how you could see her brilliant smile when she knew she could do some things finally by herself.

This invention can’t only stop here, and other projects to develop this idea are already being carried out.

For example, scientists can see how this creation can be attached to wheelchairs and other devices to help assist the disabled.

Also, although this looks more into the future, Leigh Hochberg, the leader of this , says these studies can help create a technology so that people with paralysis or amputations can recover

This outstanding experiment was not only an important scientific breakthrough, but it also made a woman that has been in silence for 15 years able to ‘move’ by herself and even drink only using her mind.

Sources Used:

http://www.newscientist.com/article/mg21428654.100-braincontrolled-arm-could-beat-paralysis.html

http://www.nytimes.com/2012/05/17/science/bodies-inert-they-moved-a-robot-with-their-minds.html?_r=1

http://www.bbc.co.uk/news/health-18087949