"quantum Tunnelling Composite" New pressure sensitive smart phone technology

[dangerdan 0]

An exploit of a quantum mechanics trick known as quantum tunnelling has allowed smart phone developers to develop pressure sensitive touch screens and keys. Potential uses could include pressing down harder to scroll faster and the enabling of 3D interfaces.

 

Theres a BBC article about it here http://news.bbc.co.uk/2/hi/science/nature/8504373.stm

 

if anyone could explain this concept of quantum tunnelling outside of this application it would be appreciated.

[shadowx 0]

This is going to be fairly inaccurate, but it should suffice (unless you happen to be stephen hawking, in which case this is just going to seem very wrong....)

Before i start, there is one thing you must understand about the quantum world. It is NOTHING like the "normal" rules that we are used to (where energy/matter cant be created destroyed, things can be in only one spot at one time etc...)

For example, the electrons whizzing around a nucleus of an atom, they dont orbit it like the moon and the earth, no. They disappear and re-appear all the time. Flashing in and out of existence. If there was one electron you might see 3 or 4 or zero as the electron can be in more than place at the same moment of time, or in no places (ie it doesnt exist).

Now, quantum tunnelling is thus: Imagine a brick wall, and you are kicking a ball at it and it bounces back. That is how things work normally if you fire an electron or sub-atomic particle at another particle (where the electron is the ball and the other atom or particle or molecule is the wall) However, in the quantum world, if you kick the ball hard enough it will go straight through the brick wall without actually causing any damage or anything, almost as if the wall wasnt there, like a ghost it would just go straight through.

So, in this mobile phone screen they have a single layer of these molecules which have this weird property. The theory is this, you fire electrons through it and normally they will bounce off like the ball does to the wall, however, some may pass through but very few. Then when you press the screen the slight pressure causes the surface to deform slightly, bringing some of these particles, or walls, closer together. This raises the chances of the electron (or ball) passing through them. So if you measured the number of electrons that make it through then you can work out how hard the screen is being pressed and hence get pressure sensitivity from it.

Source: http://en.wikipedia.org/wiki/Quantum_tunnelling

It's not the best article but it explains it and has a couple of animations too