Shadow-mask evaporation through monolayer-modified nanostencils

Gradual clogging of the apertures of nanostencils used as miniature shadow masks in metal evaporations can be reduced by coating the stencil with self-assembled monolayers (SAM). This is quantified by the dimensions (height and volume) of gold features obtained by nanostencil evaporation as measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). An increase in material deposition through the apertures by more than 100% can be achieved with SAM-coated stencils, which increases their lifetime

A Multi-Platform Flow Device for Microbial (Co-) Cultivation and Microscopic Analysis

Novel microbial cultivation platforms are of increasing interest to researchers in academia and industry. The development of materials with specialized chemical and geometric properties has opened up new possibilities in the study of previously unculturable microorganisms and has facilitated the design of elegant, high-throughput experimental set-ups. Within the context of the international Genetically Engineered Machine (iGEM) competition, we set out to design, manufacture, and implement a flow device that can accommodate multiple growth platforms, that is, a silicon nitride based microsieve and a porous aluminium oxide based microdish. It provides control over (co-)culturing conditions similar to a chemostat, while allowing organisms to be observed microscopically. The device was designed to be affordable, reusable, and above all, versatile. To test its functionality and general utility, we performed multiple experiments with Escherichia coli cells harboring synthetic gene circuits and were able to quantitatively study emerging expression dynamics in real-time via fluorescence microscopy. Furthermore, we demonstrated that the device provides a unique environment for the cultivation of nematodes, suggesting that the device could also prove useful in microscopy studies of multicellular microorganisms

Occupational Determinants of Musculoskeletal Disorders

International audienc

Patterned magnetic thin films for ultra high density recording

The areal bit density of magnetic disk recording has increased since 1990 60% per year and even in the last years 100%. Extrapolation of these rates leads to recording parameters not likely to be achieved without changes in the present way of storing hard disk data. One of the possible solutions is the development of so-called patterned magnetic media. Such media will also shift the superparamagnetic limit positively in comparison with the present thin film media. Theoretically, a bit density in the order of Tbits/in 2 may be possible by using this so-called discrete magnetic recording scheme. The patterned structures presented in this paper consist of a regular two-dimensional array of single domain dots with large uniaxial magnetic anisotropy and have been prepared from CoNi/Pt multilayers with strong intergranular exchange coupling and large perpendicular magnetic anisotropy. For the preparation of the patterned media, a patterning process based on Laser Interference Lithography method (LIL) and Ion Beam Etching has been developed. This technology provides the possibility to pattern 2-D arrays of submicron dots smaller than the critical size for the transition from multi to single domain. The smallest prepared dot sizes are 60 nm with a center-to-center dot spacing of 200 nm and thickness of 30 nm. The magnetic characterization of these dots showed that they are single domain with reasonable coercivity and good thermal stability. Micromagnetic simulations show that the single domain state is the lowest energy state for dots with a diameter below 75nm, which confirms the experimental observations