Cell Concentration and Separation in the Field of a Standing Ultrasonic Wave for Medicine and Biotechnology

Separation of Microparticles from Suspension Utilizing Ultrasonic Standing Waves in a Piezoelectric Cylinder Actuator

“…A new type of h-shaped ultrasonic resonator was applied to separate biological particles in [12]. Another study was performed on yeast cells and the red blood cells of rats and guinea pigs in a standing ultrasonic wave in order to identify the empirical boundary conditions of their concentration and separation [13]. An innovative acoustic filter, created using a multilayered piezoelectric resonator for the purpose of retaining mammalian cells in cell culture fermentations, was presented in [14].…”

Aspects of Applicability King - St. Clair Approximation in a Non-Newtonian Fluid Mechanics

“…This paper presents the theoretical analysis of the mechanisms of the action of drift forces on cells in fluid in a standing ultrasonic wave. The results of our research are the next step to a controlled ultrasonic separation of red cells in human blood [7][8][9]. Summing up the considerations it can be stated that: a) The radiation drift force directs cells to nodes or loops of the ultrasonic wave.…”

Scaling-up ultrasound standing wave enhanced sedimentation filters

“…The absorption coefficients a are 0.03 Np m À1 for water [15] and 1.4 Np m À1 for blood [16]. However although sound absorption within the fluid is low, device heating is a problem and therefore for almost every apparatus with more than 1 ml of fluid in the resonant chamber; air, water or Peltier cooling is used [13,[17][18][19][20]. In one exception to this, heating is permitted and a thermal equalization period is introduced [21].…”

“…These few devices are very successful for handling fluid volumes scales from cm 3 to m 3 but when very small scale, very large scale, high flow rates or continuous flow are needed these standard devices have limited development potential. At the sub-millilitre scale there are several particle manipulation processes based on physical characteristics which promise to increase the scope of microfluidic applications, for example electrostatic [1] and magnetic attraction [2], thermophoresis [3], microthermal field-flow fractionation (micro-TFFF), shear-induced particle migration [4], sedimentation based field-flow-fractionation [5], dean-flow inertial-focusing [6], electrowetting [7,8], optical traps [9], dielectrophoresis [10] and ultrasound-standing-wave particle filtration [11][12][13]. This last process, the subject of this paper, can in principle also be scaled up and it can also operate with: gas or liquid suspension phases; high or low media conductivity; and opaque or transparent samples.…”