tattoos of the future.

I am doing my paper on tattoos in the future. I've found some interesting information on ultra violet tattoos, 3D tattoos and electronic tattoos. All of it sounds pretty weird but in the future anything could happen. I ask myself what are the possibilities of these futuristic tattoos? Are they safe? Are they safer than normal tattoos? What are the risks? I have no answers to any of these questions but my paper will address all of them.