Tag Archives: 2-photon lithography

2-photon lithography yields precise 3D printing

Engineers had best watch out because the chemists are coming. According to a March 12, 2012 news item on Nanowerk, a multidisciplinary team at the Vienna University of Technology (TU Vienna) has devised a technology for creating extremely detailed and precise 3D nanoscale objects,

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. …

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.

3D-printing is not all about mechanics – chemists had a crucial role to play in this project too. “The resin contains molecules, which are activated by the laser light. They induce a chain reaction in other components of the resin, so-called monomers, and turn them into a solid”, says Jan Torgersen. These initiator molecules are only activated if they absorb two photons of the laser beam at once – and this only happens in the very center of the laser beam, where the intensity is highest. In contrast to conventional 3D-printing techniques, solid material can be created anywhere within the liquid resin rather than on top of the previously created layer only. Therefore, the working surface does not have to be specially prepared before the next layer can be produced … , which saves a lot of time. A team of chemists led by Professor Robert Liska (TU Vienna) developed the suitable ingredients for this special resin.

The March 12, 2012 press release includes accompanying images and video from Vienna Technical University. I have embedded the video in this posting largely because it provides a contrast to some of the more processed and visually enhanced materials that one usually finds,

As the researchers note, this is extraordinary detail.