Researchers Create New Method of High Speed Sintering 3D Printing

Researchers at the University of Sheffield have come up with a new way of utilizing High Speed Sintering (HSS) 3D printers. These printers print using a heat sensitive carbon black ink, which is laid down on powder prior to an infrared lamp being passed over it. This lamp then heats those sections of the powder that have the black ink. However, researchers have made a machine that is capable of printing in different shads of the carbon black ink (shades of grey), thus allowing the printer to print objects of varying degrees of density. This means that objects could be extremely dense in one section while being less dense, thus lighter in weight on other sections. Read more about this amazing breakthrough at http://3dprint.com/11138/high-speed-...g-3d-printers/

http://3dprint.com/wp-content/uploads/2014/08/hss1.jpg

Seems very limited, as you would have to have a powder that absorbs the ink, and the ink would always be a contaminant.
It does give me an idea of how to create different densities in an object simply, if anybody is interested...