German company Nanoscribe has introduced its 3D printer, called The Photonic Professional GT, for micro-objects measured in microns here at Photonics West.
A laser lithography method has been developed using a galvo mirror system to enable the rapid 3D printing of small objects. A galvo mirror system is similar to those used in laser show devices or scanning units of CD and DVD drives. According to Nanoscribe, reflecting a laser beam off the rotating galvo mirrors facilitates rapid and precise lateral laser focus positioning.
Nanoscribe's CEO Martin Hermatschweiler explains: 'The demands for precision and speed at the same time are met by industrially established galvo scanners. Using the novel system, the time required for printing a miniature [toy] spacecraft was reduced from hours to minutes without any loss in structure quality.'
The galvo technology, at its highest resolution, has a scanning field that is physically limited to a diameter of a few 100µm. Therefore the respective scanning fields must be connected seamlessly and accurately and Nanoscribe uses an autofocus technique with high-precision positioning stages to extend the area by stitching togther the scanned areas. As the objects are 3D, the limit on the overall structure height is imposed by the limited working distance of the microscope
The laser writing technique is based on two-photon polymerisation. Ultra-short laser pulses polymerise photosensitive materials in the laser's focus. This polmerisation renders the lased material insoluble. What hasn't been polymerised with the laser can then be washed away.
Nanoscribe was founded in 2007 as the first spin-off of the Karlsruhe Institute of Technology that specialised in the area of 3D laser lithography.