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Prototype of calorimetric flow microsensor

“…Afterwards a silicon nitride layer around 0. 15 thick is applied to the surface of the planar side of the plate. The following layer applied on a planar side of the plate is a doped polycrystalline silicon in order to form electric conductors, resistance of which depends on the temperature.…”

“…With the use of previously formed labels a photolithography process is carried out in order to obtain the topology of the plate's surface as a whole, in particular lines for scribing and membranes etching masks are formed. In the membrane area on the non-planar side of the plate the monocrystalline silicon is etched to [10][11][12][13][14][15][16][17][18][19][20] thickness, which is sufficient to provide mechanical strength to carry out further operations.…”

“…Indeed, the process of heat and mass transfer in channels depends on multiple factors such as the regime of the gas flow [11], the type and the size of the channel [12;13], the chemical composition of the channel's surface and the kind of gas [14][15][16], temperature distribution on the surface [17], roughness of the surface [18] and the pressure ratio [19]. The heat and mass transfer is also influenced by the macroscopic and physical properties of the gas.…”

Impact of the gas-surface scattering and gas molecule-molecule interaction on the mass flow rate of the rarefied gas through a short channel into a vacuum

“…4,5 With this purpose, we calculated gas flow through a tube using the test particle Monte Carlo method and compared it with the experiment results. In particular, by simulating the flow of helium through a tube with an atomically clean surface of silver or titanium, we obtained the lowest diffusion coefficient value ͑ = 0.71͒ represented in open literature for the rarefied gas flow through a capillary of finite length into a vacuum.…”

“…4,5 Thus, it is possible to suppose that for rarefied gas flow in capillaries at large pressure difference, such as when gas expands into a vacuum, the range of change of parameter is between 1 ͑diffuse scattering͒ and 0.71 ͑specular-diffuse͒. Therefore, to evaluate the impact of gassurface scattering on rarefied gas flow through a capillary into a vacuum, these two extreme cases need to be studied.…”