Novel rectangular yokeless current transducer with the range 400 A using 16 microfluxgate sensors around the busbar conductor is presented in this paper. Compared to yokeless transducers utilizing the differential pair of magnetic sensors, our solution has much better suppression of the external currents (lower crosstalk). Compared to industrial transducers with yoke, the new transducer has 15-times lower noise, 7-times better temperature stability, and same crosstalk. Sensor design and design of current monitoring system is presented together with the results of long-term field tests. Crosstalk error is examined in dependence on the number of the operating sensors and external current position.

• Klíčová slova
• circular sensor array, current sensor, finite element modelling, microfluxgate sensors,
• Publikační typ
• časopisecké články MeSH

A microfluidic device made of polydimethylsiloxane was developed for continuous evaluation of natural migration mobility of many eukaryotic cells in relaxed and deformed state. The device was fabricated by standard photolithography and soft lithography techniques using the SU-8 3010 negative photoresist on a glass wafer as the master mold. The simple flow-free device exploits the chemotactic movement of cells through a set of mechanical barriers in the direction of concentration gradients of attractants. The barriers are formed by arrays of circular cross-section pillars with decreasing spacing 7, 5, and 3 μm. To pass through the obstacles, the cells are deformed and change their cytoskeletal architecture. The instantaneous migration velocities of cells are monitored in a time-lapse setup of the scanning confocal microscope. Thus, the cellular deformability and migratory activity can easily be evaluated. The functionality of the device was tested with model HeLa cells stably transfected with fluorescent Premo FUCCI Cell Cycle Sensor. The designed device has the potential to be implemented for testing the tendency of patients' tumors to metastasis.

• Klíčová slova
• Cell deformability, Cell mobility, Confocal microscopy, Metastasis, Microfluidics,
• MeSH
• buněčné kultury přístrojové vybavení   MeSH
• design vybavení MeSH
• dimethylpolysiloxany chemie   MeSH
• HeLa buňky MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• mikrofluidní analytické techniky přístrojové vybavení   MeSH
• pohyb buněk fyziologie   MeSH
• tvar buňky fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• baysilon MeSH Prohlížeč
• dimethylpolysiloxany MeSH