Electrovibration
Electrovibration is based on an effect in which touch receptors in the skin can be duped into perceiving texture. Electrical charges simulate the feeling of localized vibration and friction, mimicking shapes, textures and contours (such as the feel of a keyboard key or a button) on touchscreens on tablets and other mobile devices or product surfaces. No electrical charge passes through the skin as the charge is created through movement over a conductive surface. A periodic electrostatic force is created, which “deforms” the skin on the finger.
http://www.chinaz.com/news/2012/1029/279959.shtml
http://www.pdp.com.cn/news/56014_.shtml
http://www.ifanr.com/31332
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http://www.gartner.com/it-glossary/electrovibration/
http://www.chuangyejia.com/archives/18884.html
http://www.edn.com/electronics-products/other/4368356/Localized-haptics-grabs-handheld-game-displays-with-new-driver-chip
TI haptic driver