Soon, fingers will be able to sense the third dimension by virtue of a supersensitive thin film that harnesses quantum tunneling to sense force. This will allow novel gaming-, artistic- and control-gestures, such as searches that dig deeper into a file structure by pressing harder.
Today, smartphones use either inexpensive resistive (Nokia C5) or more expensive capacitive (Apple iPhone) technologies, both of which have advantages and disadvantages. However, a new kind of overlay--called Quantum Tunneling Composite (QTC)--provides the best of both worlds. Additionally, QTC enables touch screens to recognize 3D gestures. Already used to add the sense of touch to the fingertips of NASA's Robonaut, Peratech has now licensed its QTC technology to Samsung for 3D joysticks, and to Nissha Printing for 3D touch screens in smartphones and tablets.
Spiked nanoparticles aid in quantum tunneling to allow Peratech's film to sense a continuum between feather-light and heavy touches, thereby enabling 3D gestures.
The QTC Clear overlay can be added to any capacitive touch screen, or can completely replace a traditional resistive touch screen. Capacitive touch screens today cannot sense force, whereas QTC adds a readout of the force being exerted on a screen by a touch, resulting in easier manipulation of on-screen objects as well as enabling 3D gesture recognition. This property can be used in a variety of applications including novel gaming interfaces to artistic expression using variable line widths depending on the force exerted.
Besides enabling 3D gesture recognition, QTC can also drastically cut the power consumed by capacitive touch screens. Today, capacitive touch screens must be constantly "on and ready" to sense touches, but adding the QTC film, a finger can switch the capacitive layer "on" only when a finger is resting on it.
QTC overlays are less than eight microns thick, consists of two layers of transparent conductors sandwiched between plates of glass. Unlike resistive touch screens which must be made of a soft polymer in order to deflect enough to be sensed, QTC overlays can sense, through glass, deflections of just a few thousandths of a millimeter.
The key to the QTC technology is its use of spike-shaped nanoparticles embedded in a transparent insulator. Quantum tunneling works because electrons are actually waves, which take a finite distance to dissipate when they hit an insulating medium. By adding spikes to the shape of normally round nanoparticle conductors, the quantum likelihood of an electron wave traversing the insulator, in which the nanoparticles of the film are suspended, is increased, thereby making QTC overlays much more sensitive than traditional films.
Peratech's force-sensitive films are already being used by NASA, the Defense Department, and several robot makers to add tactile sensing capabilities to everything from textiles to articulated hands. Next QTC overlays, being readied by Nissha, will enable the technology's first foray into touch-screen-based devices.