Asymmetric Microchannel Research Articles

Numerical simulation of cooling performance of heat sink designed based on symmetric and asymmetric leaf veins

Improvements in electrical equipment urgently require corresponding high efficiencies of heat-dissipation devices. The fractal tree-like network inserted in a heat sink to obtain an increased heat transfer coefficient and a lower pressure drop has been widely researched. However, the leaf vein networks as a high efficient transfer structure employed as microchannels in heat sinks have been rarely studied, especially regarding the effect of the tertiary microchannels on heat transfer and fluid flow that has not been mentioned by researchers. In this study, the heat sink with and without symmetric and asymmetric tertiary microchannels are considered for heat transfer when the branching angle between the primary and the secondary microchannels changes. To simulate the reticulate network of the leaf veins, the Voronoi diagrams are employed for comparison with the real Oosmanthus leaf veins. The results show that with the increase of the branching angle of the heat sink with secondary microchannels, the vortex at the branching site is enhanced and the pumping power is increased a little. Comparing with the heat sinks with secondary microchannels, the heat sink with tertiary microchannels has better performance of flow and heat transfer because it has bigger heat transfer area and there is more cooling water flow through the tertiary microchannels. As for the heat sinks with tertiary microchannels, a smaller branching angle is better for water flow through the tertiary microchannels, thereby generating more and stronger vortexes and finally improving the heat transfer performance of the heat sink. In addition, it is found that comparing to the heat sinks with symmetric tertiary microchannels, the heat sinks with asymmetric tertiary microchannels have better performance of water flow and heat transfer, despite their heat transfer area is smaller. A larger density of the tertiary microchannels causes a smaller pumping power and thermal resistance, which is optimal for improving of the flow and heat transfer performance of the heat sink designed by leaf vein structure and the comparison between the simulation and real leaf vein structure indicates that the Voronoi diagram can be employed to simulate the reticulate leaf vein.

Electrothermal analysis in two-layered couple stress fluid flow in an asymmetric microchannel via peristaltic pumping

Being motivated from the recent developments in biomicrofluidics, a mathematical model is presented to analyze the two-layered electrothermal flow via peristaltic propulsion of couple stress fluids caused by velocity and thermal slip conditions. An asymmetric microchannel is considered for the flow regime with different zeta potential moving with wave velocity. Couple stress fluid has been taken for aqueous solution to represent the non-Newtonian characteristics of physiological fluids. A lubrication approach with Debye H $$\ddot{u}$$ ckel linearization is taken to obtain the analytical solution. Furthermore, heat transfer analysis is performed to analyze the thermal characteristics and variations in Nusselt number in the presence of thermal radiation. The study shows that the temperature reduces with increasing the electrical double layer thickness, thermal radiation, couple stress parameter, and magnitude of Brinkman number, however, it enhances with increasing the Joule heating and thermal slip effects. The rate of heat transfer enhances with Joule heating effects, while the trend is reversed due to the presence of two-layered electroosmotic flow and couple stress effect.

Entropy generation in electromagnetohydrodynamic water based three Nano fluids via porous asymmetric microchannel

Nanofluids are of immense importance to the researchers as they have significant uses industrially due to their high heat transfer rates. This new model is employed to examine the electroosmotic flow of magnetohydrodynamic nanofluids through an asymmetric microfluidic channel. Microchannel flow is driven by the electroosmosis and peristalsis mechanisms. Nanoparticles (copper, alumina and titania) with water as a base fluid have been considered. The effects of Joule heating, mixed convection, permeability of the porous medium and dissipation of energy are considered. Besides, velocity slip conditions are also encountered at the walls. Electroosmotic phenomenon is modeled through Poisson equation and Nernst–Planck equation. Debye–Hückel approximation is considered to obtain Boltzmann distribution of electric potential across electric double layer. The emerging non-linear mathematical model is solved numerically by the built-in scheme of working software. The table is inserted for numerical values of heat transfer rate at the upper wall for three different type of water-based metallic nanofluid. To verify the accuracy of results, the comparison of solutions is also shown. Entropy generation in terms of Bejan number under different parameters is also investigated. The influence of physical factors on the characteristics of heat transfer has been pointed out. Water-based copper and titania nanofluids have relatively higher temperature and heat transfer rate when compared to the alumina-water nanofluid. Porosity decays the temperature throughout the microchannel. Moreover, temperature is strongly increased for higher values of the Joule heating parameter γ, in presence of Cu-water nanofluid. The current analysis is related to bio-inspired electrokinetic nanofluidic micropump models and incipient nanomedicine technologies.

Study of EDL phenomenon in Peristaltic pumping of a Phan-Thien-Tanner Fluid through asymmetric channel

This paper is mainly attained to examine the electric double layer (EDL) phenomena and rheological effects on peristaltic pumping through asymmetric microchannel in presence of Lorentz force. To examine the electroosmosis mechanism, Poisson-Boltzmann equation is considered. To describe the rheological behavior of the fluids, a Phan-Thien-Tanner model is taken into account. The governing equations are simplified by using scaling analysis with low Reynolds number and large wavelength approximations. The set of non-linear partial differential equations are solved by regular perturbation technique to find out the series solutions for stream function, axial velocity and pressure gradient. Furthermore, the shear stress at the channel wall is derived. The graphical results for velocity, pressure gradient, stream lines and shear stress are illustrated using the in-house code written in Mathematica software. It is revealed that velocity field, shear stress and trapping phenomenon are strongly altered with EDL thickness, electric and magnetic fields. It is further concluded that rheological parameter i.e. Weissenberg number significantly affects the physical mechanisms. This model can be applicable in various complex systems where the rheological fluids can be transported by novel microfluidics peristaltic pumps.

Numerical simulation of Electrokinetically Driven Peristaltic Pumping of Silver-Water Nanofluids in an asymmetric microchannel

This article intends to focus on the theoretical and numerical investigation of the peristaltic pumping of water-based silver nanofluid in the presence of electroosmotic forces. The investigation is carried out in an asymmetric microchannel subject to the influence of mixed convection and viscous dissipation. No-slip boundary conditions for velocity, temperature, and nanoparticle volume fraction are imposed on channel walls. The lubrication approach is utilized to simplify the normalized constitutive equations. The distribution of electric potential in the electric double layer is characterized by Poisson-Boltzmann ionic distribution which is further linearized by Debye-Hückel approximation. Nanofluid properties are predicted by a combination of the Buongiorno two-phase mixture model and homogeneous flow model. Additionally, the effective thermal conductivity and dynamic viscosity of silver-water nanofluid are characterized by the Corcione model. Silver nanoparticles of 20nm diameter are utilized in this suspension. The transformed set of nonlinear and coupled equations is numerically executed for axial velocity, temperature, and nanoparticle volume fraction by employing the mathematical software Maple 17. Pumping and trapping phenomena are also investigated. A comparison between the thermal conductivity of nanofluid predicted by the Corcione model and the Maxwell model is further presented. The influence of various flow parameters is outlined through graphical results. It has been observed that the thermal conductivity of silver-water nanofluid enhances with increasing nanoparticle volume fraction and temperature but decreases for larger sized nanoparticles. Moreover, the heat transfer rate rises significantly when smaller silver nanoparticles are suspended in water. Furthermore, the temperature of nanofluid is directly related to the Debye length parameter and the Helmholtz- Smoluchowski velocity parameter.

Numerical simulation of double diffusive convection and electroosmosis during peristaltic transport of a micropolar nanofluid on an asymmetric microchannel

A numerical computation is performed to analyze the double diffusive convection in micropolar nanofluids flow governed by peristaltic pumping in an asymmetric microchannel, in the presence of thermal radiation and an external magnetic field. The highly nonlinear governing equations are diluted by using desirable physical assumptions such as lubrication approximation and low zeta potential. Convective boundary conditions are employed. This enables us to determine numerical estimates of various physical flow variables such as velocity, pressure gradient, spin velocity, temperature of the nanofluid, concentration of solute, and volume fraction of nanoparticles for sundry parameters like micropolar parameter, coupling parameter, solutal Grashof number, thermophoretic diffusion coefficient, Grashof number, thermal radiation parameter and Helmholtz–Smoluchowski velocity with the aid of bvp4c function built-in command of MATLAB 2012b. Influence of each relevant parameter on flow, thermal and species characteristics are computed in this study. Influence of Soret and Dufour parameters are also simulated. This model is applicable to the study of chemical fraternization/separation procedures and various thermal management systems like of heat sinks, thermoelectric coolers, forced air systems and fans, heat pipes, and many more.

Thermal, microrotation, electromagnetic field and nanoparticle shape effects on Cu-CuO/blood flow in microvascular vessels

A thermal analysis of Cu-CuO/ blood nanofluids flow in asymmetric microchannel propagating with wave velocity is presented in this study. For the blood, a micropolar fluid model is considered to investigate the microrotation effects of blood flow. Thermal radiation effects and the influence of nanoparticle shape, electric double layer thickness, and electromagnetic fields on the flow are studied. Three types of nanoparticles shapes namely cylinder, bricks and platelets are taken into account. Governing equations are solved under the approximations of long wavelength, low Reynolds number, and Debye-Hückel linearization. Numerical computations are performed for the axial pressure gradient, axial velocity, spin velocity and temperature distribution. The effects of various physical parameters on flow and thermal characteristics are computed and their physical interpretation is also discussed. The outcomes indicate that the axial velocity of Cu-CuO/blood nanoparticles strongly depends on applied electromagnetic field and microrotation. The model's finding will be applicable in designing the smart electromagnetic micro pumps for the hemodialysis and lungs-on-chip devices for the pumping of the blood.

Electro-osmotic flow of hydromagnetic dusty viscoelastic fluids in a microchannel propagated by peristalsis

A theoretical study is carried out to determine the electric and magnetohydrodynamics of a dusty Jeffrey fluid containing small particles propagating through a wavy asymmetric microchannel. A static transverse magnetic field is applied in the presence of an electric field. Slip effects are considered to examine the flow behavior. The dusty Jeffrey model is taken into account to review its response. The governing flow problem is modelled with the help of ionic Nernst Planck equation, Poisson–Boltzmann equation, and Debye length approximation. It is then transformed into a steady wave frame with the help of coordinate transformation. Using the lubrication approach (“long wavelength and zero's Reynolds number”) the normalized governing equations of fluid and particle-phase that corresponds to the second order coupled partial differential equations represents the contribution of Jeffrey fluid model. The linearized boundary value problem is solved analytically, and exact solutions are presented for axial velocity distribution, wall shear stress and pressure gradient. It is reported from the obtained results that the magnitude of the particle-phase is more as compared to fluid-phase for velocity field and shear stress however it is less for pressure gradient. The findings of the present model are applicable in designing the microfluidics devices for the use of various transport phenomena in micro level where particles as well as fluids are transported together. The present study can be further extended and applicable for three-dimensional profile with appropriate assumptions and modifications.

Influence of Joule heating and wall slip in electroosmotic flow via peristalsis: second law analysis

Electrokinetic peristaltic slip transport in an asymmetric porous microchannel is studied to explore the entropy production in steady magnetohydrodynamic Jeffery fluid under simulation of Debye and long-wavelength approximations. The emerging two-dimensional bounded problem with electrokinetic body forces is solved numerically. Appropriate combination of heat and momentum equations with Jeffery model, after non-dimensionalization, generated controlling parameters in order to determine velocity, pressure gradient, temperature, entropy production and Bejan number. The trapping mechanism is also visualized by drawing streamlines against governing parameters. The zeta potential signifies the flow and heat response of the system. Former parameters like Brinkman number and Joule heating are compatibly liable for the increase in thermal irreversibilities. The outcomes of the present analysis are applicable in designing the thermofluidic micropumps and biomicrofluidic devices for separation processes and diagnosis.

Comparative study of hybrid nanofluids in microchannel slip flow induced by electroosmosis and peristalsis

In this paper, a mathematical model is developed to investigate the electroosmotic flow of hybrid nanoliquids (containing dissimilar nanoparticles) through an asymmetric microchannel which moves sinusoidally with constant wave velocity under an axial electrical field. The effects of Joule heating are included. Maxwell and Brinkmann correlations are employed for nanoliquid thermal conductivity and viscosity. To study the performance of hybrid nanofluids, a selection of nanofluids is examined with water as the base fluid which is doped with titania, alumina or copper metallic nanoparticles. The boundary conditions include velocity slip and thermal slip at the microchannel walls. The Debye–Hückel linearization is employed. Numerical computations for velocity, pressure gradient and temperature fields are executed in the MATLAB bvp4c routine. The influence of selected physical parameters on the flow characteristics, pumping characteristics, and temperature distribution are computed. Pressure gradient is elevated with stronger buoyancy, i.e., higher thermal Grashof number and also electroosmosis parameter, whereas it is suppressed with greater velocity slip and thermal slip parameters. Axial flow is strongly accelerated with increasing Joule heating parameter and velocity slip. Periodic behavior is observed for axial pressure gradient for all three metallic nanoparticles due to the sinusoidal nature of the pumping. With increasing Brinkman number (dissipation parameter), the axial pressure gradient is decreased for alumina (Al2O3). The temperature is strongly increased with greater Joule heating parameter across the microchannel width for Cu–water nanoliquid. The temperature is increased for (Al2O3)–water nanofluid in the left microchannel half space with increasing thermal Grashof number, whereas it is decreased in the right half space. The temperatures are enhanced for titania (TiO2)–water nanoliquid in the left half space with greater velocity slip parameter, whereas they are diminished in the right half space. The present analysis is relevant to bio-inspired electrokinetic nanofluid micropump designs and emerging nanomedicine technologies.

Convective heat transfer and double diffusive convection in ionic nanofluids flow driven by peristalsis and electromagnetohydrodynamics

An analytical study to investigate the double diffusive convection in peristaltic pumping of ionic nanofluids through asymmetric microchannel under the influence of electromagnetohydrodynamics (EMHD) is presented. Thermal radiation effect is also considered. Velocity slip and convective boundary conditions are employed at the permeable channel walls. Debye Huckel linearisation is considered to simplify the Poisson–Boltzmann equation. The normalised two-dimensional conservation equations for mass, momentum, energy, solutal concentration and nanoparticle fraction are reduced when long wavelength and low Reynolds number are assumed. Analytical solutions are computationally illustrated with MATLAB software to describe the pumping, flow and thermal characteristics under the effects of relevant parameters like Biot number, slip parameters, thermal radiation, Debye length, Hartmann number and Grashof numbers. Furthermore, solutal concentration, nanoparticle fraction and heat transfer coefficient are also analysed to see the influences of pertinent parameters. Such observations may be applicable to develop electro-osmotically actuated bio-microfluidic systems for smart drug delivery and microlevel physiological transport.

Dynamics and modelling of bubble formation in asymmetric parallel microchannels

Dynamics of gas-liquid two-phase flow in parallel microchannels is the bottleneck to be solved during numbering-up. This paper focuses on the stability and distribution of gas-liquid two-phase flow in asymmetric parallel microchannels. Nitrogen and glycerol-water solutions are used as the gas and liquid phases respectively. The stability of bubble formation is better under higher flow rates of gas and liquid phases. When the flow rate ratio of gas and liquid phases is smaller, the uniformity of bubbles is better. The design of cavities in the microchannel degrades stability, while results in better uniformity. The uniformity of the bubble size is the best in the microchannel configuration with both cavities in the front and the rear. The predictive models of the relative deviation E(L), representing the uniformity of bubbles, are proposed according to the principle of conservation of pressure drop and the resistance relationship in the parallel microchannels.

Thermal slip and radiative heat transfer effects on electro‐osmotic magnetonanoliquid peristaltic propulsion through a microchannel

AbstractA mathematical study is described to examine the concurrent influence of thermal radiation and thermal wall slip on the dissipative magnetohydrodynamic electro‐osmotic peristaltic propulsion of a viscous nanoliquid in an asymmetric microchannel under the action of an axial electric field and transverse magnetic field. Convective boundary conditions are incorporated in the model and the case of forced convection is studied, that is, thermal and species (nanoparticle volume fraction) buoyancy forces neglected. The heat source and sink effects are also included and the diffusion flux approximation is employed for radiative heat transfer. The transport model comprises the continuity, momentum, energy, nanoparticle volume fraction, and electric potential equations with appropriate boundary conditions. These are simplified by negating the inertial forces and invoking the Debye–Hückel linearization. The resulting governing equations are reduced into a system of nondimensional simultaneous ordinary differential equations, which are solved analytically. Numerical evaluation is conducted with symbolic software (MATLAB). The impact of different control parameters (Hartmann number, electro‐osmosis parameter, slip parameter, Helmholtz–Smoluchowski velocity, Biot numbers, Brinkman number, thermal radiation, and Prandtl number) on the heat, mass, and momentum characteristics (velocity, temperature, Nusselt number, etc) are presented graphically. Increasing Brinkman number is found to elevate temperature magnitudes. For positive Helmholtz–Smoluchowski velocity (reverse axial electrical field) temperature is strongly reduced, whereas for negative Helmholtz–Smoluchowski velocity (aligned axial electrical field), it is significantly elevated. With increasing thermal slip, nanoparticle volume fraction is also increased. Heat source elevates temperatures, whereas heat sink depresses them, across the microchannel span. Conversely, heat sink elevates nanoparticle volume fraction, whereas heat source decreases it. Increasing Hartmann (magnetic) parameter and Prandtl number enhance the nanoparticle volume fraction. Furthermore, with increasing radiation parameter, the Nusselt number is reduced at the extremities of the microchannel, whereas it is elevated at intermediate distances. The results reported provide a good insight into biomimetic energy systems exploiting electromagnetics and nanotechnology, and, furthermore, they furnish a useful benchmark for experimental and more advanced computational multiphysics simulations.

Hydrodynamic Microparticle Separation Mechanism Using Three-Dimensional Flow Profiles in Dual-Depth and Asymmetric Lattice-Shaped Microchannel Networks.

We herein propose a new hydrodynamic mechanism of particle separation using dual-depth, lattice-patterned asymmetric microchannel networks. This mechanism utilizes three-dimensional (3D) laminar flow profiles formed at intersections of lattice channels. Large particles, primarily flowing near the bottom surface, frequently enter the shallower channels (separation channels), whereas smaller particles flowing near the microchannel ceiling primarily flow along the deeper channels (main channels). Consequently, size-based continuous particle separation was achieved in the lateral direction in the lattice area. We confirmed that the depth of the main channel was a critical factor dominating the particle separation efficiencies, and the combination of 15-μm-deep separation channels and 40-μm-deep main channels demonstrated the good separation ability for 3–10-μm particles. We prepared several types of microchannels and successfully tuned the particle separation size. Furthermore, the input position of the particle suspension was controlled by adjusting the input flow rates and/or using a Y-shaped inlet connector that resulted in a significant improvement in the separation precision. The presented concept is a good example of a new type of microfluidic particle separation mechanism using 3D flows and may potentially be applicable to the sorting of various types of micrometer-sized objects, including living cells and synthetic microparticles.

Asymmetric straight-through microchannel arrays made of aluminum for producing monodisperse O/W emulsions

The aim of this study was to stably produce monodisperse food-grade oil-in-water (O/W) emulsions using an asymmetric straight-through microchannel (MC) array that is microfabricated on an aluminum chip. Circular MCs of the inlet side were fabricated using a microdrilling process, while microslots of the outlet side were fabricated by electric discharge machining. We used refined soybean oil as the dispersed phase and a Milli-Q water solution containing 1 wt% Tween 20 as the continuous phase. An aluminum MC array with a circular MC diameter (dMC) of 116.9 μm produced monodisperse O/W emulsion droplets with an average diameter (dav) of about 300 μm and coefficients of variation (CVs) below 4%, whereas an aluminum MC array with 82.1 μm diameter stably generated monodisperse O/W emulsion droplets with dav of about 150 μm and CVs below 4%. The dav of the produced oil droplets was affected by the dimensions of asymmetric straight-through MCs. Monodisperse O/W emulsions were successfully generated below the critical dispersed-phase flow rate, with little variation in dav and CV values. The force balance during droplet generation was also analyzed for discussing the results for the effect of the dispersed-phase flow rate.

Entropy generation on electromagnetohydrodynamic flow through a porous asymmetric micro-channel

Abstract We analyze the heat transfer phenomena in a narrow confinement filled with Couple Stress fluid (taking into account molecule size effect) driven by the simultaneous influence of pressure gradient, electrical potential and the peristaltic pumping in the presence of magnetic field. The effects of Joule heating, permeability of the porous medium and dissipation of energy are taken into account. Entropy generation in terms of Bejan profile and the Nusselt number under different parameters are investigated. The analytical method has been invoked to find the closed from solution of the thermo-fluidic governing equations. The study reveals that the zeta potential has significant importance in controlling velocity and thermal response in the system. The Joule heating effect and Brinkman number both are equally responsible for enhancement of thermal irreversibility measured in terms of Bejan number profile. Thus the study bears potential applications in industrial and biomedical technology for developing microfluidic devices.

Peristaltic motion of MHD nanofluid in an asymmetric micro-channel with Joule heating, wall flexibility and different zeta potential

A mathematical scrutiny is introduced for the flow of magneto-hydrodynamic nanofluid through an asymmetric microfluidic channel under an applied axial electric field. The impacts of wall flexibility, Joule heating and upper/lower wall zeta potentials are considered. Electric potential expressions can be modeled in terms of an ionic Nernst–Planck equation, Poisson–Boltzmann equation and Debye length approximation. Appropriate boundary conditions have been utilized to get the results of highly nonlinear coupled PDEs numerically. The impact of physical factors on the characteristics of flow, pumping, trapping and heat transfer has been pointed out. The outcomes may well assist in designing the organ-on-a-chip like gadgets.

Demulsification of Kerosene/Water Emulsion in the Transparent Asymmetric Plate-Type Micro-Channel.

Asymmetric plate-type micro-channels (APM) have one hydrophobic wall and one hydrophilic wall. By flowing through APM, a kerosene-in-water emulsion can be de-emulsified in one second. To date, however, the demulsification process in the APM is still a black box. In order to observe the demulsification process directly, transparent asymmetric plate-type micro-channels (TAPM) were fabricated with two surface-modified glass plates. Emulsions with oil contents of 10%, 30%, and 50% were pumped through TAPM with heights of 39.2 μm and 159.5 μm. The movement and coalescence of oil droplets (the dispersed phase of a kerosene-in-water emulsion) in the TAPM were observed directly with an optical microscope. By analyzing videos and photographs, it was found that the demulsification process included three steps: oil droplets flowed against and were adsorbed on the hydrophobic wall, then oil droplets coalesced to form larger droplets, whereupon the oil phase was separated. The experimental results showed that the demulsification efficiency was approximately proportional to the oil content (30–50%) of the emulsions and increased when the micro-channel height was reduced.

Peristaltic flow of Eyring-Powell nanofluid under the action of an electromagnetic field

Electro-kinetic peristaltic flow of Eyring-Powell nanofluid has been investigated in this paper. The flow is considered to take place in an asymmetric wavy micro-channel. The system is supposed to be acted on by an external magnetic field and to be exposed to Joule heating. Velocity and temperature of the fluid have been calculated by using Debye-Hückel approximation. Flow of the nanofluid is considered to take place under the combined action of an external transverse magnetic field and a horizontal static electric field. Considering low Reynolds number and using long wavelength approximation, variations of axial velocity, pressure gradient, wall shear stress and temperature profiles have been investigated both analytically and numerically by using efficient mathematical softwares. The peristaltic pumping characteristics and the trapping of fluid bolus have also been thoroughly examined in the light of electroosmosis. The study shows that even mild electroosmosis can cause higher pressure gradient in the axial direction. It bears the promise of important application to weak peristaltic transport modulation for EMHD nanofluid flows. The study further reveals that the occurrence of trapping can be controlled by suitably adjusting the magnitude of the electric field. The study also reports the thermal transport mechanism in the fluid, under the action of Joule heating and viscous energy dissipation. It shows that an increase in the volume fraction of the nanoparticles in the fluid can considerably enhance the momentum transport in the core region of the microchannel.

Asymmetric sifter-shaped microchannel network in biological MEMS for size- and mass-based mammalian cell sorting and separation using hydrodynamic technique

A peculiar method used for particle separation device in microfluidics is hydrodynamic filtration. To achieve the filtration of sample fluid with particle, this is the technique which concedes two-input (with buffer inlet) sheath fluid to conflow at distinct velocity rates in a sifter-shaped microchannel network demonstrated. The objective is to assure the separation of particles based on size and mass in microflow network with grooves or rectangular cross section by hydrodynamic filtration. However, simulation is done to examine the particle tracing with mass by sifter-shaped microchannel network using COMSOL Multiphysics software. The size, mass and density of the particle are related to the properties of K. pneumoniae and blood particles samples. During the experiments, different networks were designed and simulated to acquire a better filtration effect and particle separation based on size and mass. After the simulation done for the networks, it resulted that sifter-shaped microchannel network shows a precise separation of K. pneumoniae particle. Analysis of a microchannel having distinct angles (90°, 15°, 25° and 35°) with individual inflow velocity for sample with particle and buffer inflow velocity without particle at 3000 µl/s and with various other flow rates for blood and 50 µl/s and with various other flow rates for water was performed, where sifter-shaped microchannel device consisting of 90° and 25° sifter structure provides a preferable separation through the targeted outlet 4 and outlet 1 of microchannel for a larger bioparticles and smaller particles (blood cells) through the other outlets of device.