Label-free segmentation of co-cultured cells on a nanotopographical gradient

The function and fate of cells is influenced by many different factors, one of which is surface topography of the support culture substrate. Systematic studies of nanotopography and cell response have typically been limited to single cell types and a small set of topographical variations. Here, we show a radical expansion of experimental throughput using automated detection, measurement, and classification of co-cultured cells on a nanopillar array where feature height changes continuously from planar to 250 nm over 9 mm. Individual cells are identified and characterized by more than 200 descriptors, which are used to construct a set of rules for label-free segmentation into individual cell types. Using this approach we can achieve label-free segmentation with 84% confidence across large image data sets and suggest optimized surface parameters for nanostructuring of implant devices such as vascular stents

SUB-MICRON SCALE PATTERN TRANSFER INTO POLYMERS BY THERMAL IMPRINT LITHOGRAPHY

Nanoimprint lithography (NIL) is an emerging patterning technology which shows the capability of fabricating nanostructures on a large scale. It is therefore interesting for low-cost NEMS manufacturing. As schematically shown, a stamp made of single crystalline silicon is pressed into a thermoplastic polymer at a temperature above its glass transition temperature TG. After the cavities of the stamp are filled with the polymer, the stamp is removed at a temperature below TG. The resulting residual layer can be removed by anisotropic dry etching, if necessary. Our goal is first to find suitable process parameters for the existing equipment in CMI and to establish a NIL process line. We have succeeded to replicate structures into thin polymer layers reproducibly with sub-micron feature sizes on a wafer scale. This technology will serve as a basis for a variety of applications and a research tool in the sub-micron range