Mobile Touch Screens Could Soon Feel the Pressure

Forget swiping or pinching--the next generation of portable touch-screen devices will be able to distinguish between a gentle touch and a hard poke.
Peratech, a U.K. company, has signed a $1.4 million deal to license its pressure-sensing touch-screen technology to Japanese screen manufacturer Nissha, which makes displays for companies including LG and Nintendo. Peratech's technology is one of several approaches that can be packed into portable devices. But it uses a novel quantum mechanism to sense pressure, and this promises to be more sensitive and more efficient than the other approaches.
Peratech, which was spun out of a research lab at Durham University in 1996, uses an electrically conductive material dubbed a quantum tunneling composite (QTC). Quantum tunneling occurs when electrons jump between two conductors that are brought close together, but remain separated by an insulating barrier. In Peratech's switches, a polymer acts as the insulating layer. It is embedded with spiky, conductive metallic particles, each about 10 nanometers in size.
"These are polymer materials that change their resistance as force is applied," says Philip Taysom, Peratech's CEO. So as force is applied, these particles are brought closer together. "As they come into proximity, they allow quantum tunneling," he says.
The approach allows Peratech's QTC sensors to be extremely thin: just 75 micrometers thick. The sensors line the perimeter of a display. When pressure is applied and the screen bends very slightly (as little as two micrometers), the switches detect this change. By comparing the readings from the sensors with sensory data from the touch screen, it is possible to tell precisely where, and how hard, the screen is being pressed

Thanks Technology Review