Part of the show Naked Science Question and Answer
The days of indelibly pledging your undying love for someone by tattooing their name across your forehead, only to regret it later, are finally over. Thankfully for those tempted to have "sharon forever" etched into their dermis, dermatologist Rox Anderson, from the Massachusetts General Hospital in Boston, has developed a way to produce erasable tattoos. He has found a way to encapsulate tattoo dyes within tiny polymer beads measuring between 1 and 3 thousandths of a millimetre across. When these "dye capsules" are scratched into the skin they are picked up by skin cells which then take on the colour of their encapsulated cargo, forming a tattoo. But if you decide subsequently that you don't like what you see, or "Sharon" becomes "Sherin" (or even "Kevin"), a single blast with a laser can wipe the slate clean. It works because the laser breaks open the capsules, spilling the coloured contents that they contain, which is then absorbed and broken down. This is a marked improvement on existing tattoo technology which, in addition to using dyes that are also used in car paints and contain toxic chemicals such as heavy metals, can only be removed 50% of the time and only then following fairly aggressive laser skin treatments.