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). 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 polymerized line of solid polymer, just a few hundred nanometers wide. This high 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.
This amazing progress was made possible by combining several new ideas. "It was crucial to improve the control mechanism of the mirrors," says Jan Torgersen (TU Vienna). The mirrors are continuously in motion during the printing process. The acceleration and deceleration-periods have to be tuned very precisely to achieve high-resolution results at a record-breaking speed.