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Spatially defined neuronal networks have great potential to be used in a wide spectrum of neurobiology assays. We present an original technique for the precise and reproducible formation of neuronal networks. A PDMS membrane comprising through-holes aligned with interconnecting microchannels was used during oxygen plasma etching to dry mask a protein rejecting poly(ethylene glycol) (PEG) adlayer. Patterns were faithfully replicated to produce an oxidized interconnected array pattern which supported protein adsorption. Differentiated human SH-SY5Y neuron-like cells adhered to the array nodes with the micron-scale interconnecting tracks guiding neurite outgrowth to produce neuronal connections and establish a network. A 2.0 μm track width was optimal for high-level network formation and node compliance. These spatially standardized neuronal networks were used to analyse the dynamics of acrylamide-induced neurite degeneration and the protective effects of co-treatment with calpeptin or brain derived neurotrophic factor (BDNF). [ABSTRACT FROM AUTHOR]

Abstract LIGA is the basic idea of promising developments for the manufacturing of microelectromechanical system parts containing high aspect ratio microstructures. Aim of the work is a brief discussion of the starting-points for inline process inspection within a direct LIGA technology using deep X-ray lithography for the production of micromechanical gear wheels with critical dimensions of ?35??m width at ?1?mm height as well as to show methodic and technical measuring possibilities. Firstly, results of the determination of residual solvent content distribution within ultra-thick SU-8 films are shown obtained from refracted near field optical measurements. Furthermore, the capability of X-ray computer tomographic imaging is discussed and measurements for the determination of the three-dimensional shape of high aspect ratio microstructures are practically demonstrated with microscopic and interferometric optical methods. Finally, first results demonstrate the potential of the optical coherence tomography for several further important measurement tasks, among others, e.g. for the imaging of the distribution of mechanical stress at the resist?substrate interface. The results show that much information which is essential in the LIGA process can be achieved with recently available measurement methods. However, further development of non-destructive measurement techniques would be desirable for an effective inline process control of mass production of micromechanical parts. [ABSTRACT FROM AUTHOR]