Nanolithography printer replacing conventional electronics

The world’s fastest 3D printer of micro- and nanostructures has been developed. With this printer, smallest three-dimensional objects, often smaller than the diameter of a human hair, can be manufactured with minimum time consumption and maximum resolution. The printer is based on a novel laser lithography method.

The printer was developed by Nanoscribe GmbH, a spin-off of Karlsruhe Institute of Technology (KIT).

Last year, 18 spin-offs were established at KIT. The 3D laser lithography systems developed by Nanoscribe - the spin-off can still be found on KIT’s Campus North - are used for research by KIT and scientists worldwide. Work in the area of photonics concentrates on replacing conventional electronics by optical circuits of higher performance. For this purpose, Nanoscribe systems are used to print polymer waveguides reaching data transfer rates of more than 5 terabits per second.

By means of the new laser lithography method, printing speed is increased by a factor of about 100. This increase in speed results from the use of a galvo mirror system, a technology that is also applied in laser show devices or scanning units of CD and DVD drives. Reflecting a laser beam off the rotating galvo mirrors facilitates rapid and precise laser focus positioning.

The direct laser writing technique underlying the 3D printing method is based on two-photon polymerisation. Just as paper ignites when exposed to sunlight focused through a magnifying glass, ultrashort laser pulses polymerise photosensitive materials in the laser focus. Depending on the photosensitive material chosen, the exposed or unexposed volume only is dissolved. After a developer bath, these written areas remain as self-supporting micro- and nanostructures.

By means of the galvo technology, three-dimensional micro- and nanostructures can be printed rapidly and, hence, on large areas in principle. At highest resolution, however, the scanning field is limited physically to a few 100 µm due to the optical properties of the focusing objective. Just as floor tiles must be joined precisely, the respective scanning fields have to be connected seamlessly and accurately. By the so-called stitching, areas can be extended nearly arbitrarily.