Scientists from the Forschungszentrum Jülich GmbH and the DWI e.V. in Aachen, Germany, have addressed these questions and evaluated the influence of polymer composition on pattern fidelity during imprinting with an air cushion press system by Nanonex (NX-2000). They found that the corresponding variations in the mechanical properties of the stamps play a minor role in the deformation behaviour of the investigated polymer. Instead, the scientists found that the size of the pattern element is a critical issue and that features of decreased size are more sensitive to pattern distortions than larger patterns.

Sandra Gilles and her co-workers optimized the design by increasing the structure density and using constant size ratios between lines and spaces to improve pattern fidelity. Imprints performed on the basis of these design rules resulted in reduced deformations and repealed size dependence. The observed relation between pattern dimensions and degree of deformation has to be carefully considered during the design of future nanoimprint lithography layouts based on soft moulds to improve the performance of this technique when downscaling feature sizes.

Currently the team employs soft UV NIL to locally address biomolecules to electronic junctions or to apply chemical nanopatterns to functional surfaces. The group is working towards locally controlled adhesion of neurons on device surfaces by biochemical clues to guide the cells into defined neuronal networks.

The researchers presented their work in the journal Nanotechnology.