چكيده به لاتين
Abstract:
Today there is a lot of tendency to use analytical micro-systems in the field of molecular and
microbial diagnostics, Because benefits like low space, reduced sample and reagent
consumption, reduced analysis time and more. The rotational microfluidic are a sub branch
of the microfluidic branch, which, using centrifugal forces, causes the fluid to flow in the
networks enclosed in disk-shaped rotating systems. These networks can carry out chemical
or biological analyzes, and ultimately lead to the creation of a device capable of replacing
conventional devices for medical diagnosis.
One of the most commonly used elements in microfluidic systems is the separation element.
This element is used to separate particles in the sample according to specifications such as
mechanical (density and size), chemical, electrical, etc. The use of this element in studies
such as cancer, the separation of particles attached to specific antibodies, and many others
are seen.
In this research, different methods of separation based on mechanical and chemical
characteristics have been investigated and an optimal method for separating different
particles is presented based on these specifications. The idea of using a spiral microchannel
simultaneously utilizes three separation mechanisms (centrifugal and Coriolis Force due to
the disk rotation and centrifugal Force due to the Spiral channel curvature) in a network
succeeded in isolating 90% of the silica particles present in the sample and Finally, the fluid
was collected at a purity of 98.15%. The results of the experiments indicated that increasing
the rotational speed and spiral microchannel length would improve the separation process
and increase the efficiency. In the next step, in order to better analyze the behavior of
particles within the microchannel, numerical simulation was performed and validated by the
experimental results. Numerical results showed that increasing the diameter and density of
particles would improve the separation process. The linear velocity of the particle motion in
the channel increases with increasing rotational velocity and as a result increased Coriolis
force, which results in higher efficiency of the collection. Therefore, by changing the existing
parameters and optimizing them, one can use the suggested microchannel according to the
needs of the set and design in the microfluidic networks.
Keywords: Microfluidics, centrifugal microfluidics, lab-on-a-disc, Separation, Spiral
microchannel
