New submitter drunkdrone quotes a report from International Business Times: Spanish scientists say they have developed a prototype 3D printer that is capable of printing "functional" human skin that can be used for transplant patients, as well as an ethical alternative to animal testing. The so-called bioprinter uses special "ink" consisting of human cells and other biological components to reproduce the natural structure of the skin, including the external epidermis and the deeper dermis layer. These "bio inks" are deposited from special injectors onto a print bed to produce skin that is bioactive and capable of producing its own human collagen, the researchers claim. This means that the 3D-printed skin is, in essence, living tissue, making it suitable for treating burn patients and for testing cosmetic, chemical and pharmaceutical products. According to UC3M, the technology could be used to print other human tissues, although first it needs to be approved by regulators in order to ensure the skin it produces is fit for use on human patients.