While looking around I discovered a demo of Toshiba's tactile feedback system here. I assume that the display is set up to provide a small electrical current that has enough power so that our sense of touch can detect it. Is this actually how this system works?
If so, what kind of current and voltage needs to be provided to be detectable by touch? Would we be able to detect DC as well as AC?
If anyone has any references or source material on what the ranges of human perception are for this type of effect, I would appreciate it.