3D-printer with nano-precision

3D-printer with nano-precision
A 285 µm racecar, printed at the Vienna University of Technology

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 , just a few hundred wide. This 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 , this is a world record.

The video shows the 3d-printing process in real time. Due to the very fast guiding of the laser beam, 100 layers, consisting of approximately 200 single lines each, are produced in four minutes.

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.

3D-printer with nano-precision
A model of St. Stephen's Cathedral, Vienna. Credit: Klaus Cicha

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 , 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 (see Video), which saves a lot of time. A team of chemists led by Professor Robert Liska (TU Vienna) developed the suitable initiators for this special resin.

3D-printer with nano-precision
The London Tower Bridge. Credit: Klaus Cicha

Researchers all over the world are working on 3D printers today – at universities as well as in industry. “Our competitive edge here at the Vienna University of Technology comes from the fact that we have experts from very different fields, working on different parts of the problem, at one single university”, Jürgen Stampfl emphasizes. In materials science, process engineering or the optimization of light sources, there are experts working together and coming up with mutually stimulating ideas.

Because of the dramatically increased speed, much larger objects can now be created in a given period of time. This makes two-photon-lithography an interesting technique for industry. At the TU Vienna, scientists are now developing bio-compatible resins for medical applications. They can be used to create scaffolds to which living cells can attach themselves facilitating the systematic creation of biological tissues. The 3d printer could also be used to create tailor made construction parts for biomedical technology or nanotechnology.


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Citation: 3D-printer with nano-precision (2012, March 13) retrieved 14 October 2019 from https://phys.org/news/2012-03-3d-printer-nano-precision.html
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Mar 13, 2012
This is a real breakthrough! Great Job!

Mar 13, 2012
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Mar 13, 2012
50 µm is about the width of a human hair. These things are barely visible to the naked eye.

Which means that it's possible to take a proper photograph of them using light and a microscope instead. I'd like to see one.

Mar 13, 2012
This is one of the most exciting articles I've read on PhysOrg!

Mar 14, 2012
This is one of those rare moments when technology suddenly seems to take a giant leap forward all at once.

Mar 14, 2012
This comment has been removed by a moderator.

Mar 14, 2012
physorg.com/news/2010-12-laser-3d-submicron.htm l

Mar 16, 2012
Could someone please comment as to how big of a breakthrough this is? It seems huge, but as I don't have any expertise in the subject I would like to know from someone who does.

Thanks

Mar 17, 2012
I am very excited for the bio-compatible version. The idea that we can construct scaffolds with nano-scale precision means we'll be able to build/grow complex organs in a lab, like a heart, a liver maybe even an eyeball. That's a huge deal for people waiting on transplant lists.

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