March 14, 2012 
Printing three dimensional objects with incredibly fine details is now possible using “two-photon lithography”. With this technology, tiny structures on a nanometer scale can be fabricated. Researchers at the Vienna University of Technology (TU Vienna) have now made a major breakthrough in speeding up this printing technique: The high-precision-3D-printer at TU Vienna is orders of magnitude faster than similar devices (see video below). This opens up completely new areas of application, such as in medicine.
The 3D printer uses a liquid resin, which is hardened at precisely the correct spots by a focused laser beam. The focal point of the laser beam is guided through the resin by movable mirrors and leaves behind a hardened line of solid polymer, just a few hundred nanometers wide. This fine resolution enables the creation of intricately structured sculptures as tiny as a grain of sand. “Until now, this technique used to be quite slow”, says Professor Jürgen Stampfl from the Institute of Materials Science and Technology at the TU Vienna. “The printing speed used to be measured in millimeters per second – our device can do five meters in one second.” In two-photon lithography, this is a world record.
Using biological materials, robotisits at Cornell University in the U.S have developed the first prosthetic ear from silicone materials using a 3D printer. It is hopeful that this is the first step in developing functional body parts by engineering three dimensional tissue constructs, instrumental in aiding in reconstructive medicine. The system works by collecting the dimensions and distribution of healthy human tissue through MRI scanning, which is then stored, to then be utilised in the development of body parts should they ever be injured. A gantry system is integrated in the printer with the ability to deposit materials precicely within the 3D space to ensure intricasy in design. It is predicted that the technology will be fully developed an utilised within the next two decades.
