RESUMO
Removal or exact transfer of minimum substance volumes from reservoirs or microfluidic systems may be accomplished by means of miniaturized tips with integrated through-going capillaries. Applications in biomedical engineering, e.g. for the application of drugs, or in life sciences, e.g. equipping of microarrays, require the use of disposable plastic products for hygienic reasons and reasons of costs. For this purpose, a method to fabricate microtips out of plastic by doublesided molding has been developed at the Forschungszentrum Karlsruhe.
Assuntos
Equipamentos Descartáveis , Sistemas de Liberação de Medicamentos/instrumentação , Miniaturização/instrumentação , Plásticos , Disciplinas das Ciências Biológicas/instrumentação , Engenharia Biomédica/instrumentação , Desenho de Equipamento , HumanosRESUMO
The catalytic CVD synthesis, using propyne as carbon precursor and Fe(NO3)3 as catalyst precursor inside porous alumina, gives carbon nanotube (CNT) bags in a well-arranged two-dimensional order. The tubes have the morphology of bags or fibers, since they are completely filled with smaller helicoidal CNTs. This morphology has so far not been reported for CNTs. Owing to the dense filling of the outer mother CNTs with small helicoidal CNTs, the resulting CNT fibers appear to be stiff and show no sign of inflation, as sometimes observed with hollow CNTs. The fiber morphology was observed by raster electron microscopy (REM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The carbon material is graphitic as deduced from spectroscopic studies (X-ray diffraction, Raman and electron energy-loss spectroscopy (EELS)). From Mössbauer studies, the presence of two different oxidation states (Fe0 and FeIII) of the catalyst is proven. Geometric structuring of the template by two different methods has been studied. Inkjet catalyst printing shows that the tubes can be arranged in defined areas by a simple and easily applied technique. Laser-structuring creates grooves of nanotube fibers embedded in the alumina host. This allows the formation of defined architectures in the microm range. Results on hydrogen absorption and field emission properties of the CNT fibers are reported.
RESUMO
The research activities of the Forschungszentrum Karlsruhe on minimally-invasive surgery (MIS) have for several years improved techniques and instrumentation for different types of MIS. Many types of instruments and robotic devices have been developed and new techniques implemented. In this paper we present the most recent results from our different projects, such as endoscopic heart surgery, tracking systems, a camera guidance device, telemanipulator systems, minimally-invasive breast biopsy in closed-bore MRI, endoscopic training simulators and developments using smart materials (e.g. Nitinol).
