Another group working on machinery to produce tissue engineered blood vessels: "German researchers have been working at growing tissue and organs in the laboratory for a long time. These days, tissue engineering enables us to build artificial tissue, although science has still not been successful with larger organs. Now researchers at the Fraunhofer group of applied research institutes are applying new techniques and materials to come up with artificial blood vessels in their BioRap project that will be able to supply artificial tissue and, perhaps, even complex organs in the future. ... The aim of tissue engineering is to create organs in the laboratory for opening up new opportunities in the field. Unfortunately, researchers have still not been able to supply artificial tissue with nutrients because they do not have the necessary vascular system. Five Fraunhofer institutes joined forces in 2009 to come up with biocompatible artificial blood vessels. It seemed impossible to build structures such as capillary vessels that are so small and complex and it was especially the branches and spaces that made life difficult for the researchers. But production engineering came to the rescue because rapid prototyping makes it possible to build workpieces in line with any complex three-dimensional (3D) model. Now scientists at Fraunhofer are working on transferring this technology to the generation of tiny biomaterial structures by combining two different techniques: 3D printing technology established in rapid protoyping and multiphoton polymerisation developed in polymer science."