Tactile Pixels

Soon it will be possible to To Read Braille On Touchscreens

Senseg technology applies an innovation in biophysics to bring a haptic effect to the traditionally passive touch user interface.

Senseg's new E-sense technology, could bring real-world touch into everyday computing.
Obviously, this is nothing new. Research into programmable friction has already yielded impressive results with changing stickiness.

But this concept accomplishes the same goal by using "tixels" or tactile pixels to create an electrical field you can feel. Your skin responds by feeling whatever the interface wants it to feel: Buttons, perhaps, or even the fur of a virtual pet.
The project sounds really promising, and Senseg already has Toshiba backing them. Imagine video chat aided by tactile pixels.
http://senseg.com/technology/senseg-technology

Senseg E-Sense makes use of an electro-sensory phenomenon that replicates the feeling of touch. As very tiny electrical charges pass into the tixel elements, the individual tixels generate a controlled electric field which extends several millimeters above the surface. Senseg E-Sense is a wholly new way of creating a sophisticated sensation of touch without the use of less sensitive haptic technology like vibration or mechanical actuators such as motors, piezoelectric actuators or electro-active polymers.


The Senseg E-Sense principle
Based on the principle of attraction force between charges, Senseg effects creates a sophisticated sensation of touch. By passing an ultra-low electrical current into the insulated electrode – the tixel – the proprietary charge driver can create a small attractive Coulomb force to finger skin. By modulating this attractive force, any number of touch sensations can be generated from vibrations, clicks, textured surfaces and more.


University of British Columbia has another method for doing similar.

The friction adjustment is actually something of a trick. The surface of the screen itself is made of glass and does not become rougher or smoother. Instead, the glass is made to vibrate at around 26,000 Hz by a series of small mechanical discs that sit at the edge of the screen. This creates a thin film of moving air on top of the glass, which has the effect of making the screen feel stickier. By adjusting the vibrations in response to finger movements across the glass, the system can create a convincing illusion in which objects appear to bump into each other or stick to things.

From Gizmodo:
http://gizmodo.com/5819701/tactile-pixels-will-make-it-easy-to-read-braille-on-touchscreens
http://gizmodo.com/5801371/future-touchscreens-might-have-adjustable-stickiness-factor
http://www.newscientist.com/blogs/onepercent/2011/05/programmable-friction-makes-to.html