Development, fabrication and testing of a microfluidic chamber for dielectrophoretic field-flow separation of biological cells based on their electrical properties is described. The chamber was constructed from a single Pyrex wafer with interdigitated Au electrodes, a spacer, and a top cover glass, making the events in the chamber observable under most optical microscopes. A 93% efficiency of separation was obtained, confirming the usefulness of the chamber in separating cells with sufficient differences in electrical properties of their membranes.
COBISS.SI-ID: 8331860
Thermal annealing of deposited Ti/Pt layers in the temperature range of 300-700 °C was investigated revealing strong impact on the Ti/Pt resistivity. Furthermore, it was determined that temperature coefficient of resistance (TCR) for Ti/Pt temperature sensors and the heater increased with the annealing temperature. Microstructural analysis of deposited and annealed Ti/Pt layers carried out by AES and AFM revealed that recrystallization followed by grain growth process of heat treated Ti/Pt layers started at around 500 °C and correlated well with the behavior of electrical properties. Additional insulation steps of assembled microfluidic platform further reduced the power consumption, but also increased the time response of the microfluidic reactor.
COBISS.SI-ID: 8160596
The paper presents solutions for residual stress control in thin films deposition on plasma enhanced chemical vapor depositions (PECVD) reactors and some MEMS applications. The main layers analyzed are: amorphous silicon, amorphous silicon carbide and amorphous silicon nitride. The main parameters analyzed are the temperature of the deposition process, pressure, gas composition, as well as the value of the power and the power mode (high frequency - 13.56 MHz or low frequency – 400 KHz. The RF frequency mode presents a major influence of residual stress: in low frequency mode a relatively high compressive stress is achieved due to ion bombardment and, as a result, densification of the layer is achieved.
COBISS.SI-ID: 8972116