Tattoos may seem like they’re everywhere, and no longer taboo. But widespread medical use of tattoos has been limited because of the need for repeated needle injections that can be painful and carry risks of bleeding and infection.

Now scientists have developed a way to avoid these deterrents: a tattoo patch containing microscopic needles that can quickly color skin without causing pain or drawing blood. These single-use microneedle tattoo patches work for both color images and for markings visible only with ultraviolet illumination, according to a study published September 14 in iScience… Continue reading.