Researchers led by Pankaj Karande at the Rensselaer Polytechnic Institute (RPI) in coordination with Yale University have now 3D printed living, working skin tissue by reducing human skin cells to a liquid called “bio ink,” which is only a little bit gross. The scientists have also figured out how to affect the pigment of the 3D skin, to suit any ethnicity. Melanocytes can be added to the bio ink in greater or lesser numbers depending on the color desired. But there is more work left to do in order to make the 3D skin as human-like and safe as possible. You want the skin at the graft site to look as much like the surrounding skin.”Unfortunately 3D printing sweat glands has shown less spectacular results.