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We have developed a highly integrated lab-on-a-chip containing embedded electrical microsensors, μdegassers and pneumatically-actuated micropumps to monitor allergic hypersensitivity. Rapid antigen-mediated histamine release (e.g. s to min) and resulting muscle contraction (

The human placenta is a unique organ serving as the lung, gut, liver, and kidney of the fetus, mediating the exchange of different endogenous as well as exogenous substances and gases between the mother and fetus during pregnancy. Additionally, the placental barrier protects the fetus from a range of environmental toxins, bacterial and viral infections, since any contaminant bridging the placenta may have unforeseeable effects on embryonal and fetal development. A more recent concern in placenta research, however, involves the ability of engineered nanoparticles to cross the placental barrier and/or affect its barrier function. To advance nanoparticle risk assessment at the human placental barrier, we have developed as proof-of-principle a highly integrated placenta-on-a-chip system containing embedded membrane-bound impedance microsensor arrays capable of non-invasively monitoring placental barrier integrity. Barrier integrity is continuously and label-free evaluated using porous membrane-based interdigitated electrode structures located on top of a porous PET membrane supporting a barrier of trophoblast-derived BeWo cell barrier in the absence and presence of standardized silicon dioxide (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO) nanomaterials., This work has been funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 685817.

A versatile synthetic protocol toward a series of various substituted triphenylamine derivatives serving as building blocks for organic electronic materials was developed. Key steps during synthesis were either Ullmann condensations or nucleophilic aromatic substitutions giving rise to structural modification of triphenylamines and their electronic nature. In turn, these scaffolds were exemplarily attached to a dendritic tris(2-thienyl)benzene core affording star shaped organic semiconducting materials which were characterized regarding their photo-physical, electro-chemical and thermal properties. A strong influence of the substituent's nature on both photo-physical and morphological thin film characteristic of star shaped target compounds was observed. The applicability of these materials in organic electronic devices was demonstrated in an organic field effect transistor configuration yielding a hole mobility of nearly 10−3 cm2 V−1 s−1. The performance of the materials can be correlated to the substituents applied.

FIB technologies possess a unique ability to form topographies that are difficult or impossible to generate with binary etching through typical photo-lithography. The ability to arbitrarily vary the spatial dose distribution and therefore the amount of milling opens possibilities for the production of a wide range of functional structures with applications in biology, chemistry, and optics. However in practice, the realization of these goals is made difficult by the angular dependence of the sputtering yield and redeposition effects that vary as the topography evolves. An inverse modeling algorithm that optimizes dose profiles, defined as the superposition of time invariant pixel dose profiles (determined from the beam parameters and pixel dwell times), is presented. The response of the target to a set of pixel dwell times in modeled by numerical continuum simulations utilizing 1st and 2nd order sputtering and redeposition, the resulting surfaces are evaluated with respect to a target topography in an error minimization routine. Two algorithms for the parameterization of pixel dwell times are presented, a direct pixel dwell time method, and an abstracted method that uses a refineable piecewise linear cage function to generate pixel dwell times from a minimal number of parameters. The cage function method demonstrates great flexibility and efficiency as compared to the direct fitting method with performance enhancements exceeding ∼10× as compared to direct fitting for medium to large simulation sets. Furthermore, the refineable nature of the cage function enables solutions to adapt to the desired target function. The optimization algorithm, although working with stationary dose profiles, is demonstrated to be applicable also outside the quasi-static approximation. Experimental data confirms the viability of the solutions for 5 × 7 μm deep lens like structures defined by 90 pixel dwell times.

In this article, three novel cyclopentadienyl precursors are evaluated for the atomic layer deposition (ALD) of erbium oxide, with either ozone or water as the oxygen source. The erbium precursors evaluated are Er(iPrCp)3, Er(MeCp)2(iPr-amd), and Er(nBuCp)3. The films are deposited on silicon within the temperature range 200–400°C. Self-limiting growth is achieved with all three precursors, with both ozone and water. It is found that the water processes of all three precursors present significantly higher growth rates when compared to the ozone processes. An up to three-fold increase in the growth rate is observed for the water processes of Er(iPrCp)3 and Er(MeCp)2(iPr-amd) (amd: amidinate) when compared to their ozone processes. The films are smooth and uniform, as determined by atomic force microscopy (AFM) (rms roughness

Two heteroleptic titanium precursors were investigated for the atomic layer deposition (ALD) of titanium dioxide using ozone as the oxygen source. The precursors, titanium (N,N'-diisopropylacetamidinate)tris(isopropoxide) (Ti(O(i)Pr)3(N(i)Pr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe2)2(O(i)Pr)2), exhibit self-limiting growth behavior up to a maximum temperature of 325 °C. Ti(NMe2)2(O(i)Pr)2 displays an excellent growth rate of 0.9 Å/cycle at 325 °C while the growth rate of Ti(O(i)Pr)3(N(i)Pr-Me-amd) is 0.3 Å/cycle at the same temperature. In the temperature range of 275-325 °C, both precursors deposit titanium dioxide in the anatase phase. In the case of Ti(NMe2)2(O(i)Pr)2, high-temperature X-ray diffraction (HTXRD) studies reveal a thickness-dependent phase change from anatase to rutile at 875-975 °C. X-ray photoelectron spectroscopy (XPS) indicates that the films have high purity and are close to the stoichiometric composition. Reaction mechanisms taking place during the ALD process were studied in situ with quadrupole mass spectrometry (QMS) and quartz crystal microbalance (QCM).

In this article we explore the application of scanning capacitance microscopy (SCM) for studying focused ion beam (FIB) induced damage in silicon. We qualitatively determine the technologically important beam shape by measuring the SCM image of FIB processed implantation spots and by comparison of topographical and SCM data. Further, we investigate the question how deep impinging ions generate measurable damage below the silicon surface. For this purpose, trenches were manufactured using FIB and analyzed by SCM in cross-sectional geometry.

In this paper we explore the application of scanning capacitance microscopy (SCM) for studying focussed ion beam (FIB) induced damage in silicon. We qualitatively determine the technologically important beam shape by measuring the SCM image of FIB processed implantation spots, and by comparison of topographical and SCM data. Further, we investigate how deep impinging ions generate measurable damage below the silicon surface. For this purpose, trenches were manufactured using FIB and analysed by SCM in cross-sectional geometry.

A novel approach for spectroscopic trace analysis is introduced by combining surface enhanced infrared absorption (SEIRA) spectroscopy with external reflection techniques on disposable inexpensive substrates. SEIRA-active surfaces produced by electrochemical deposition of silver on smooth metal surfaces and glass improve the sensitivity of IR reflection measurements significantly since the infrared absorption of organic substances such as p-nitrobenzoic acid is considerably increased in the vicinity of rough noble metal surfaces. The enhancement properties of thus prepared substrates are characterized and compared using IR-spectroscopy. These low-cost substrates used in single- and multiple external reflection arrangements, respectively, yield a significant increase of the detection level compared to conventional reflection absorption infrared spectroscopy (RAIRS) up to one order of magnitude. Hence, a notable step towards a wide-spread application of SEIRA in routine IR reflection analysis is presented.

In Raman spectroscopy, detection limits for organic pollutants in water can be lowered by several orders of magnitude when surface enhanced techniques are applied. In this work a continuous analytical device based on flow injection analysis using SERS detection is proposed. This system was tested with model analytes such as pyridine and nicotinic acid as well as several pesticides (carbendazim, metazachlorine).

The presence of rough metal surfaces is known to increase the infrared absorption of selected analytes. It could be shown that this surface enhancement effect applies to a wide range of chemical substrates with different molecular structure, although the observed enhancement is not equivalent for all absorption bands. For carboxyl groups, interactions with the metal surface were observed suggesting the formation of an adsorption complex. Furthermore, the potential of surface enhanced infrared absorption (SEIRA) as quantitative method is demonstrated.

In order to further improve the sensitivity of chemical IR sensors, research into a significant change in the signal generation mechanism was carried out. This effort was realized by generating the surface-enhanced IR absorption and Raman-scattering effect at silver- and gold-island-covered Ge- and ZnSe ATR surfaces for surface-enhanced infrared absorption (SEIRA) and Ag-layer-covered brass plates for surface-enhanced Raman scattering (SERS), respectively, and linking the optimized tools to the IR sensor concept. By careful optimization of the generation of silver-island and gold-island films on Ge reflection elements, intensity gains by a factor of 50 were achieved. Chemical interactions between the silver-island layer and the various analytes investigated up to now (p-nitro benzoic acid, as a model compound, and selected aromatic and chlorinated pesticides) are likely, as indicated by significant IR spectral changes; the substances are, however, bound to the surfaces in a reversible manner. This property of the novel SEIRA sensor can be favorably exploited in flow-through systems. In a similar way, by a specially optimized treatment of anodically oxidized brass plates in a silver bath, repeatably usable SERS targets for the trace analysis of pesticide mixtures in aqueous systems could be developed. A signal enhancement factor of 1.4 million was obtained with pyridine as the standard sample. The data shown in this work suggest that both SEIRA and SERS can be coupled to a flow injection system in a reversible way for the molecular-specific trace analysis of organic compounds in aqueous solutions.

This paper describes the results of the 3rd Europe-wide enquiry of the Working Party on Analytical Chemistry (WPAC) of the Federation of European Chemical Societies (FECS) in the field of education of analytical chemists at university level. While the first enquiry launched in 1983/84 showed the importance of separate chairs in Analytical Chemistry for maintaining the quality of modern curricula in a rapidly changing world and the evaluation of the second questionnaire from 1989/90 was the basis of the “WPAC-Eurocurriculum”, this third enquiry (1995) was aimed at determining the impact that the WPAC-Eurocurriculum initiative has made on the “Advanced Study Schemes” in Analytical Chemistry at European universities 3 years after its announcement. From the 141 questionnaires evaluated, it could be clearly shown that the WPAC-Eurocurriculum is already well known and accepted at universities in Europe, but not yet sufficiently established. Institutions having the WPAC-Eurocurriculum already implemented, however show a more flexible, modern and application oriented approach to the advanced study programme in Analytical Chemistry than universities teaching in the old way.

Using a generalized extraction method, the fixed charge density Nint at the interface between in situ deposited SiN and 5 nm thick AlGaN barrier is evaluated by measurements of threshold voltage Vth of an AlGaN/GaN metal insulator semiconductor high electron mobility transistor as a function of SiN thickness. The thickness of the originally deposited 50 nm thick SiN layer is reduced by dry etching. The extracted Nint is in the order of the AlGaN polarization charge density. The total removal of the in situ SiN cap leads to a complete depletion of the channel region resulting in Vth = +1 V. Fabrication of a gate stack with Al2O3 as a second cap layer, deposited on top of the in situ SiN, is not introducing additional fixed charges at the SiN/Al2O3 interface.

This work shows the enhancement of spectral absorptions by noble metals (Ag, Au) deposited in nm-thick layers on the surface of ATR-crystals. By the surface-enhanced infrared absorption (SEIRA) technique, the absorption bands of p-nitrobenzoic acid can be enhanced by a factor of up to 40. This enables the detection of substance concentrations in the mM range. The structure of the metal deposit has been investigated by atomic force microscopy and correlated with the enhancement factor.