A guy in my lab played has been playing with something like this off and on for a while, for a different application. My understanding of the technology is that it requires fairly high voltage but extremely low current to work, so the power draw is rather low.

A bigger concern is what happens when you get it wet. This changes the conductive properties of the skin, so you go from a barely noticeable 'tingle' or 'friction' effect to a noticeable shock (think static shock). Thankfully, the current is too low to be dangerous in most cases, but defective circuits could still be a problem in production runs.

I'd be interested to see how this technology deals with such issues.

"as little as 8 Volts to generate tactile sensations" from http://www.teslatouch.com/technology.html

Although in their white paper, they write that it is further amplified up to 120Vpp.

It shouldn't use much power though, they note that the panel is only supplied with 0.5mA max, lower than many LED currents. They also say that it's the same amount of current used for conventional capacitive touch panels.

Finally, the paper describes the sensations produced. Users have described various settings as feeling sticky or waxy, feeling akin to touching a motorcycle handle or rubber, or running a finger through a viscous fluid.