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2021
Diploma Thesis
Titel
Characterisation of Passive Check Valves in Microsystems
Abstract
A trend towards miniaturisation can be observed in many industries. Among other things, the quest for more performance and the reduction of mass and energy consumption have favoured this trend in recent years. This is also the case in medical and laboratory technology. For some applications, micropumps offer opportunities for integration into microdosing systems and thus contribute to the miniaturisation of devices. Possible areas of application for the piezoelectric steel diaphragm micropump manufactured at Fraunhofer EMFT include negative pressure therapy for wounds, the dosage of medicines and hydraulic prostheses. Precise dosing is essential here, which is why the behaviour of all the components of the micropump must be studied in detail and the interrelationships understood. One of these complex components is the microvalve. The behaviour of passive valves is strongly dependent on the fluidic properties of the medium used. The literature research has shown that there are deficits in the investigation of microvalves with liquid as the medium. One reason for this is that the valves are not visible during normal operation of the micropump, as the actuator diaphragm is located above the valves. Therefore, no experimental measurements are known describing the behaviour of the valves under the influence of liquids. However, measurements are necessary to validate the derived valve models. For this purpose, a new measurement method is being developed to investigate the quasi-static and dynamic behaviour of valves under the influence of air and water and to characterise the valve behaviour. This opens up new possibilities for more detailed observation and derives optimisation options.
ThesisNote
Wien, TU, Dipl.-Arb., 2021
Verlagsort
Wien