Simulation of Blood Particle Separation in a Trapezoidal Microfluidic Device by Acoustic Force

Nowadays, the importance of the blood particles separation is undeniable in medical fields and there are different sorts of separation methods accordingly. Acoustic cell separation is chosen in this paper. Also, numerical methods have been used to study the effect of geometrical factors on the separation of the particles before spending time and expenses in a trial and error manner experimentally. We have implemented a plenary finite-element-based simulation of separating blood particles such as white blood cells and platelets in an acoustic field using standing surface acoustic waves. In this paper, unlike previous works in which the channel is rectangular; the channel is trapezoidal in order to make the separation more efficient. By changing the trapezoidal leg angle, WBC's distance from the midline will be different. The designed device is a bio-MEMS channel containing two inlets which are for the sheath flow and for the blood particles, a trapezoidal main channel, and three outlets. Two aluminum interdigital transducers are located on the LiNbO3 substrate. For creating the acoustic force, we have applied an alternating voltage to transducers. Blood particles will be moved toward the acoustic nodes because of the positive acoustic contrast factor. Since acoustic radiation force depends on the size of the particles and their compressibility, cells can be sorted according to their diameter and compressibility; hence, particles will be separated. For optimizing the device, we have changed the trapezoidal channel angle, the input voltage, and the flow rate.