Elastic plastic touch screen

many people still like to type on buttons rather than screen. they said type on hard flat screen feel no good, especially no feeling on what you type.

How about an elastic touch screen? when you have to type, that part of the screen will pop and curved a bit. when you press on it, it will lower and give back some push on your finger. it acts exactly like keypad.

This can also be extended for people who cannot use their eyes. the screen can pop up the letter, in big, so we can feel it with our fingers.

The curvature of the screen better be 1mm, so it can show real good letter, sharp and clear.

How? may be by air? by the Electrorheological (ER) fluids? the basic idea is just add a very thin layer on the top of the hard flat screen.