Computer Simulation Based Optimization of Aspect Ratio for Micro and Nanochannels

For Computational Fluidic Dynamics (CFD) analysis, different types of software are available such as ANSYS, COMSOL, GAMBIT and ABAQUS. ANSYS FLUENT is a very influential CFD software that enables the researchers to execute advanced and fast simulation as the performance of product is optimized. In this research work, the capabilities of ANSYS FLUENT have been investigated through the fluidic simulation of nano scale channels. Here, the simulation of three straight shaped and one curvilinear nano channel has been performed to analyze the precision of simulation with the aspect ratio of smaller dimensions (radius, length). The accurate dimensions have been determined for various shapes of channels. For straight circular channel, the radius of 124.9 µm and length of 900 µm are the dimensions found for error free simulations with 7.20 aspect ratio. While for straight crossed channel, the radius of 5.1 mm and length of 100 mm are the accurate dimensions for error free simulations with 19.60 aspect ratio. Width and depth are determined as 180 µm with 180 µm length in case of straight square channel for error free simulations with 1.0 aspect ratio. Finally, in case of curvilinear channel for error free simulations, the radius and length are found 22 and 209.1 µm respectively with 9.50 aspect ratio. None of the channels is found fit for simulation in nanometer range. Even in micrometer range, the simulations of these channels have acquired errors. Moreover, it has been observed that the aspect ratio is different for different geometries of microchannels for error free simulation.

DESIGN, SIMULATION AND COMPARISON OF ASCENDING AND DESCENDING CURVILINEAR MICROCHANNELS FOR CANCER CELL SEPARATION FROM BLOOD

Separation of rare cells such as circulating cancer and fetal cells from blood has potential importance in disease monitoring and prevention. In this paper, we report a new method of cancer cells separation from patient blood by inertial focusing technique. A design and simulation of ascending and descending curvilinear microchannels for separation of particles resembling cancer cells have been presented. In simulation, polystyrene particles have been used which represent the size of red blood cell (RBC), white blood cell (WBC) and cancer cells. Computational fluid dynamics (CFD) design and simulation of ascending and descending microchannels is used for cell separation. The simulation was carried out in two stages including focusing and separation. The ascending curvilinear channel design demonstrated favorable focusing and separation. Separation with 100% purity and efficiency of the unwanted particle was achieved at Reynolds number (Re) = 8.50 and velocity 0.105 m/s. In case of descending curvilinear channel, cell separation was not good. Considering cancer cells size about 15 μm, our proposed ascending microchannel is a good candidate for cancer cells separation from blood.

Cell Separation Through Ascending and Descending Curvilinear Microchannels

Separation of rare cells such as fetal cells from blood has potential importance in disease investigation and prevention. In this paper we report a new method of cancer cells separation from patient’s blood by inertial focusing technique. A design and simulation of ascending and descending curvilinear microchannels for separation of particles resembling cancer cells have been presented. Computational fluid dynamics (CFD) design and simulation of ascending and descending microchannels is used for cell separation. The simulation was carried out in two stages including focusing and separation. The ascending curvilinear channel design demonstrated favorable focusing and separation. Separation with 100% purity and efficiency of the unwanted particle was achieved at Reynolds number (Re) = 8.50 and velocity 0.105m/s. Reynolds number 9.25 and 10.06 with corresponding velocities 0.115 m/s and 0.125 m/s were also investigated for cell seperation. In case of descending curvilinear channel, cell separation was not good. Considering cancer cells size about 15 µm, our proposed ascending microchannel is a good candidate for cancer cells separation from blood.