Heidi Ottevaere

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We report a novel process technology of hemispherical shaped microlenses, using isotropic wet etching of silicon in an acid solution to produce the microlenses molds. Governed by process parameters such as temperature and etchant concentration, the isotropic wet etching is controlled to minimize various defects that appear during the molding creation. From(More)
The individual factors that determine the kinetic performance (B- and C-term band broadening and bed permeability Kv) of radially elongated pillar (REP) columns are studied. To this end, columns with REPs having 4 different aspect ratios (AR=9, 12, 15, 20) were characterized experimentally and by means of numerical simulations. A tortuosity and retention(More)
Microstructured optical products are becoming more widespread due to advances in manufacturing. Many of these structures contain faceted surfaces with steep slopes. Adequate metrology for such surfaces is lacking. We describe an interferometric technique that combines plane wave illumination with an index matching liquid to achieve high quality, high speed(More)
We report on a series of preliminary experiments investigating the applicability of a novel method for the size separation of nano- and microsized particles and cells. The working principle is based on the application of a shear-driven flow through stepwise tapered micro- or nanochannels. Size separations of mixtures of 0.5 and 1.0 microm carboxylated(More)
Doughnut shaped hybridization patterns on DNA microarrays are mainly allocated to spotting or drying artifacts. The present study reports on results obtained from four different approaches that when combined generate a better view on the occurrence of these patterns. This study points out that doughnuts are not only formed during the spotting and drying(More)
In conventional multichannel imaging systems, all channels have similar imaging properties [field-of-view (FOV) and angular resolution]. In our approach, channels are designed to have different imaging properties which add multiresolution capability to the system. We have experimentally demonstrated, for the first time to our knowledge, a three-channel(More)
Straightforward numerical integration of the Rayleigh-Sommerfeld diffraction integral (R-SDI) remains computationally challenging, even with today's computational resources. As such, approximating the R-SDI to decrease the computation time while maintaining a good accuracy is still a topic of interest. In this paper, we apply an approximation for the R-SDI(More)
We report on the use of a free-space optical module to establish multi-channel intra-chip optical interconnections on an opto-electronic field programmable gate-array (OE-FPGA). The optical component was prototyped and replicated in our labs to provide 2x8 parallel channels. After careful alignment of the free-space module on the OE-FPGA 4 channels were(More)
We present a quantitative study on the fabrication of microlenses using a low-cost polymer dispending technique. Our method is based on the use of a silicon micro-cantilever robotized spotter system. We first give a detailed description of the technique. In a second part, the fabricated microlenses are fully characterized by means of SEM (Scanning Electron(More)