Nokia haptikos tactile touchscreen details emerge
When RedFerret published their impressions on Nokia haptikos tactile touchscreen technology, there were pretty few details revealed about how exactly this thing will work.
What we knew then was that they have “…inserted two small piezo-sensor pads under the screen and engineered in a 0.1mm movement in the screen itself“.
Recently Nokia patent application for (apparently) this technology became public. So now we can bring you more details about how this wonder touchscreen tech will work.
The main idea behind the haptikos is the possibility to create “… variable and controllable user perceived surface roughness or friction coefficient“.
This is achieved by placing a “…plurality of closely spaced voltage controllable protuberances” that can be raised and lowered on a touchscreen surface.
When no current is applied, the protuberances are flush with the surface of touchscreen and the whole surface area feels solid and smooth. When voltage is applied, the protuberances raise from the surface with increasing extent, providing the feel of tactile elements on a touchscreen. By controlling on which parts of the touchscreen and when the protuberances are raised, and illusion of a tactile feedback is achieved.
The protuberances in the picture above are made of the elongated elements that extend parallel to the touchscreen. But they can as easily have circular or elliptic outline and can be arranged in a grid array.
The protuberances themselves consist of a transparent fluid filled compartments, covered with translucent elastic sheet or foil. Alongside these compartments are piezoelectric actuating members that protrude into them as voltage is applied. The pressure on a liquid in the compartments created by protruding actuators makes the elastic surface or the compartments to bulge out, creating the touchscreen surface area friction.
Each actuator can be controlled independently, providing the possibility to dynamically create and turn off higher surface friction/roughness areas on any part of the touchscreen, at will. By moving the actuators back further then the default position, it is even possible to create a negative pressure on the tactile feedback compartments, thus creating the feel of the surface bulging in, e.g. at a press of the button.
This tactile feedback layer is really thin and transparent, and is invisible to the user when placed above the LCD and touchscreen, or integrated into the touchscreen plane.
And the rest is the work of tuning the actuating software to create a convincing illusion of tactile elements and movement. Which is, admittedly, no easy feat.
But Nokia already has a working prototype of haptikos based touchscreen keyboard and is hard at work on drag and scrolling functions.
I hope, that by the time Nokia has it’s own S60 multi-touch UI rolling out, haptikos would be ready for a prime time too.
You can download the patent application here.