London: A UK firm has come up with a material that exploits a quantum physics trick, which could lead to the development of handheld devices with pressure-sensitive touch-screens and keys.
According to a report by BBC News, the approach, developed by Yorkshire-based Peratech, could find use in devices from phones to games to GPS handsets. A division of Samsung that distributes mobile phone components to several handset manufacturers has now licensed the "Quantum Tunnelling Composite".
In January, Japanese touch-screen maker Nissha also licensed the approach from Yorkshire-based Peratech, who make the composite material QTC.
The composite works by using spiky conducting nanoparticles, similar to tiny medieval maces, dispersed evenly in a polymer.
None of these spiky balls actually touch, but the closer they get to each other, the more likely they are to undergo a quantum physics phenomenon known as tunneling.
Tunnelling is one of several effects in quantum mechanics that defies explanation in terms of the "classical" physics that preceded it.
Simply put, quantum mechanics says that there is a tiny probability that a particle shot at a wall will pass through it in an effect known as tunneling.Similarly, the material that surrounds the spiky balls acts like a wall to electric current.
But, as the balls draw closer together, when squashed or deformed by a finger`s pressure, the probability of a charge tunneling through increases.
The net result is that pressing harder on the material leads to a smooth increase in the current through it.
There are a number of ways to make switches or screens pressure-sensitive, such as using mechanical switches.
However, the QTC approach is particularly suited to making thin devices.
Pressure-sensitive QTC switches can be made 70 micrometers thick - about the thickness of a human hair.
QTC is better than switches based on so-called "conducting polymers", because they conduct no electricity until they are pressed, leading to better overall efficiency.
Samsung Electro-mechanics has now incorporated the QTC into the navigation switch familiar on smartphones - in addition to the up, down, left, right and centre button, the up and down functions are pressure-sensitive.
This is useful for scrolling more or less quickly through, for example, a long list of emails.
"Electronics are being given the ability to sense something that we take for granted, which is how much we`re touching and applying force," Peratech`s chief executive Philip Taysom told BBC News.
First Published: Tuesday, February 09, 2010, 19:08