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JUL/AUG 2015
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Racecar sets world speed record

A 285µm-long racecar has been fabricated in record time via ultrahigh-precision 3-D printing at Vienna University of Technology.

The two-photon lithography process used allows objects with nanoscale features to be fabricated much faster than was possible previously, said a press release issued by the university.

“Printing speed used to be measured in millimeters per second,” said Jürgen Stampfl, a professor at TU Vienna’s Institute of Materials Science and Technology. “Our device can do 5 meters in 1 second.” He added that the device’s fabbing speed is a world record for two-photon lithography.

Small Car at Vienna

TU Vienna researchers developed a 3-D printing system to fabricate this 285µm car. Image courtesy TU Vienna.

The leap forward in two-photon-lithography technology was made possible by combining several new ideas, said TU Vienna’s Jan Torgersen. “It was crucial to improve the control mechanism of the mirrors. The laser focus is traced in the liquid resin using a galvanometer scanner. It has no feedback control, as this would be too slow. The synchronization of the switching of the laser—done by an acousto-optic modulator—and the movement of the mirrors was, thus, very tricky. Delay parameters of the mirrors and fast CMOS optocoupling devices made it possible.”

The university also synthesized its own resins for the project. “Commercially available resins are not suitable for this type of precision and writing speed,” said Torgersen. “The reactivity and efficiency of the formulations is as important as precise and fast mechanics.” A team of chemists led by TU Vienna professor Robert Liska developed the special resin.

The researchers report that their device could be adapted for commercial uses. TU Vienna scientists currently are developing biocompatible resins for medical applications. Scaffolds that living cells attach to could be fabricated from the resins, facilitating the systematic production of biological tissue. The 3-D printer also could be used to make customized parts for biomedical or nanotechnology applications.

To learn more about two-photon lithography—also known as two-photon polymerization—read our July/August 2010 cover story titled, “One-Step Fabbing.”