"REVEL is a new wearable tactile technology that modifies the user’s tactile perception of the physical world. Current tactile technologies enhance objects and devices with various actuators to create rich tactile sensations, limiting the experience to the interaction with instrumented devices. In contrast, REVEL can add artificial tactile sensations to almost any surface or object, with very little if any instrumentation of the environment. As a result, REVEL can provide dynamic tactile sensations on touch screens as well as everyday objects and surfaces in the environment, such as furniture, walls, wooden and plastic objects, and even human skin.
REVEL is based on Reverse Electrovibration. It injects a weak electrical signal into anywhere on the user's body, creating an oscillating electrical field around the user’s skin. When sliding his or her fingers on a surface of the object, the user perceives highly distinctive tactile textures that augment the physical object. Varying the properties of the signal, such as the shape, amplitude and frequency, can provide a wide range of tactile sensations." (from the video clip page: http://www.youtube.com/watch?v=L7DGq8SddEQ )