Microfluidic technology is a valuable tool for realizing more in vitro models capturing cellular and organ level responses for rapid and animal‐free risk assessment of new chemicals and drugs. Microfluidic cell‐based devices allow high‐throughput screening and flexible automation while lowering costs and reagent consumption due to their miniaturization. There is a growing need for faster and animal‐free approaches for drug development and safety assessment of chemicals (Registration, Evaluation, Authorisation and Restriction of Chemical Substances, REACH). The work presented describes a microfluidic platform for in vivo‐like in vitro cell cultivation. It is equipped with a wafer‐based silicon chip including integrated electrodes and a microcavity. A proof‐of‐concept using different relevant cell models shows its suitability for label‐free assessment of cytotoxic effects. A miniaturized microscope within each module monitors cell morphology and proliferation. Electrodes integrated in the microfluidic channels allow the noninvasive monitoring of barrier integrity followed by a label‐free assessment of cytotoxic effects. Each microfluidic cell cultivation module can be operated individually or be interconnected in a flexible way. The interconnection of the different modules aims at simulation of the whole‐body exposure and response and can contribute to the replacement of animal testing in risk assessment studies in compliance with the 3Rs to replace, reduce, and refine animal experiments.

This paper reports on a polymer-based piezoelectric transducer used in microfluidic structures for generating acoustic waves, and consequently, the acoustic streaming phenomenon, that will improve the mixing of fluids. The piezoelectric transducer is based on a poly(vinylidene fluoride- trifluoroethylene), P(VDF-TrFE), copolymer with conductive transparent electrodes of aluminum doped zinc oxide (AZO). The efficiency of the optimized piezoelectric P(VDF-TrFE) transducer on mixing fluids was studied using two diagnostic kits for the quantification of uric acid and nitrite in blood. In both cases, acoustic streaming reduced the reaction time for the quantification of each biomolecule when compared to the reaction time achieved only by diffusion, with gains of 23% and of 32% for the uric acid and nitrite, respectively. These results contribute to increase the efficiency in fluid mixing and therefore to improve the overall performance of miniaturized analysis systems

Today acoustic microscopy transducers are based on zinc oxide, ZnO, films as piezoelectric material. Especially in the GHz range the insertion loss of existing ZnO transducers has to be improved for better imaging. The motivation for this work was to substitute the ZnO by the piezoelectric material lead zirconate titanate, PZT, with better electro mechanical properties. Novel technologies of sol-gel and metal organic chemical vapor deposition method (MOCVD) were used to realize high frequency PZT thin film transducers with 200 m aperture diameter. The transducers were characterized by electrical and acoustical measurement. Their performance for acoustic microscopy was evaluated

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