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
This article reports a novel striptype microthrottle pump with a rectangular actuator geometry, with more efficient chip surface consumption compared to existing micropumps with circular actuators. Due to the complex structure and operation of the proposed device, determination of detailed structural parameters is essential. Therefore, we developed an advanced, fully coupled 3D electrofluidsolid mechanics simulation model in COMSOL that includes fluid inertial effects and a hyperelastic model for PDMS and noslip boundary condition in fluidwall interface. Numerical simulations resulted in accurate virtual prototyping of the proposed device, detailed operation analysis and optimization of crucial geometrical parameters.
COBISS.SI-ID: 9729620
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
Improvement of bubble tolerance and priming in micropumps based on Triton X100 surfactant is investigated. Transparent membrane piezoelectric micropumps were fabricated. Precise air volumes were introduced into the micropump chamber to emulate micropump bubble disturbance. Micropump recovery time decreased with increased addition of Triton X100 surfactant between 50100 ppm. Effective recovery is mainly a consequence of the air bubble dispersion into a foam of small bubbles. Small bubbles are then readily removed by liquid flow, leading to significant enhancement of micropump bubble tolerance.
COBISS.SI-ID: 9933140
An overview of micromachining technologies for the fabrication of silicon microstructures was given. Basic micromachining technologies such as various etching methods of silicon (isotropic, anisotropic; dry, wet) and etching of other important materials (Pyrex glass etc.), anodic bonding, etc. was discussed. For an illustration of microstructures fabrication by micromachining procedures, a review of microstructures fabricated in LMSE such as micropumps and microreactors, together with their characteristics and applications, was given.
COBISS.SI-ID: 8473940