Anybody calling their technology something as quaint as a Quantum Tunneling Composite, knows that they are going to have a tough sell when a fundamental breakthrough happens, but that’s why Faultline is here, to pick up such breakthroughs for you and ponder their significance.
A small UK company says that it has a massive breakthrough in Quantum Tunneling and the implications are that virtually immediately this will lead to cheaper touch screens, either resistive screens which are more sensitive and offer multi-touch or capacitive screens which use a fraction of the power. But it’s a big jump from the announcement data so hang on in there.
You can go to Wikipedia and look up Quantum Tunneling, but fundamentally it’s a way of changing the dielectric in a device so that a charge can pass where it once would not pass, in this case upon the application of a tiny amount of pressure. Hence touch screens.
Typically a touch screen works in two different ways, one with a dielectric of air between two substrates and pieces of glass ‘ that’s resistive screens, or by placing a charge all over the screen, which is interfered with by something like a finger creating a capacitance effect ‘ soaking up some of that charge ‘ so capacitive screens.
What we have at tiny Peratech in the UK is an existing intellectual property licensing business, based around QTC ‘ and this so far has hinged on building a polymer from very spiky metal microscopic sized particles, covered in an insulator. Most similar metal particles are roughly round, so they touch just once at their outermost edge and transferring a charge from one to another is tough. It’s easier when you push them together, but not that much easier. Hence the state of resistive touch screens, where they come with a deforming soft cover, so you have to push down hard, and this moves the cover around the depression, and creates eddies which make sensing a second touch too tricky. Which is why multi-touch isn’t worth trying with resistive screens.
By making the metal polymer out of spiky particles, when they move fractionally, the spikes touch along their sides, creating lots of surface area in contact, and a charge can jump across the insulator more easily. In a touch screen this isn’t much help since it’s tough to see through metal spikes, even if they are microscopically small, because they need to be on top of the screen, not under it. Which is why so far the Peratech system has been used on opaque screen edges in touch screens from Nissha in Japan and from Samsung in Korea.
The breakthrough is to create a composite material which is not made out of metal, but is still a combination of an insulator and something which conducts, and is still spiky for that extra contact, but which is see through.
Peratech is not telling anyone what it is made from quite yet, except under license, as the company is in the process of patenting the material. It is called
QTC Clear and this force sensing material should be used to create a whole new class of Force Sensitive touch screens that can completely replace current resistive touch screen technologies or enhance capacitive screens to potentially include 3D input.
The neat thing is that the composite is inexpensive to create, and just 6 to 8 microns of it are needed, and this can go into existing resistive manufacturing processes, without requiring a deforming layer and instead using glass screens. This has the potential to create a screen that can operate like a capacitive screen, in that it is glass, it is sensitive and it offers multi-touch.
But the trick in adding it to capacitive screens is that instead of having a constantly charged screen, complete with charge leakage and high power use, a capacitive screen can be placed in an uncharged condition and as soon as it is touched, become charged.
‘Both resistive and capacitive touch screen technologies have their drawbacks,’ explained Philip Taysom, Peratech’s Joint CEO. ‘Resistive is not very accurate and can’t do multi-touch so it is becoming less popular than Capacitive, but the latter uses a lot of power constraining it to smaller screen sizes. Our new, QTC Clear touch screen design offers the best of both technologies without their drawbacks. It can be made in any size and provides multi-touch, high sensitivity with great accuracy, ultra-low power consumption and additional intuitive features with the third dimension of pressure to more easily manipulate and control information on the screen.’
The QTC Clear layer is only 6-8 microns thick with a transparency that is very similar to the existing touch screen technologies. This is sandwiched between two layers of Indium Tin Oxide, which is in turn sandwiched between two hard sheets, typically glass. It is so sensitive that it can detect deflections of only a few microns so that the top surface can be rigid and robust. The composite’s properties means that virtually no current flows unless a force is applied. This overcomes the drawbacks of capacitive designs that constantly draw current and create design challenges to overcome interference issues with other components inside.
Peratech says that QTC Clear has already been licensed to a leading touch screen manufacturer, which we guess could be either Nissha or Samsung. Peratech is loosely attached to Durham University which has a QTC lab.