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

Abstract

A method of microparticle separation from larger volumes of suspension is proposed. A piezoelectric cylinder is selected as an ultrasonic wave actuator, the diameter and length of which the volume of the suspension to be purified depends. Numerically and experimentally, it is demonstrated that the low-level pressure field nodal circles of ultrasonic radiation standing waves concentrate microparticles at different velocities depending on the fluid viscosity. Numerical mathematical modeling has allowed us to identify the basic dynamic characteristics of the piezoelectric actuator to ensure a more effective process of microparticle separation. An important feature of the proposed method is that the ultrasonic radiation stresses that are directly applicable to cell membranes are inadequate to cause them damage.

Rapid and Efficient Computation of Cell Paths During Ultrasonic Focusing

“…A potential example is provided by the work of Stevenson et al 39 demonstrating streaks or layers of bladder "debris" on ultrasound as a predictor for positive urine cultures in a pediatric population. Similar findings were reported in adults by Wachsberg et al 40 These ultrasonically visualized debris layers (likely containing both bacteria and white blood cells) perpendicular to the ultrasonic beameven in mild cases (Figure 1A in Stevenson et al 39 )-look remarkably like the patterns of particle clumping seen in other experimental systems, including, colored zeolite particles, 16 human leukemia cells, 41 antibody coated microspheres, 4 and 10 µ diameter, 1.05 g/mL density polystyrene microspheres, 42 as well as in the simulations show in in Figures 2 to 4…”

“…Several often-cited treatments of the underlying physics describe particles suspended in compressible, inviscid fluids, such as air, subjected to inertial forces in the presence of pure acoustic standing waves. [12][13][14][15][16][17] More recently, others have specifically computed analytical formulas for acoustic focusing of particles in viscous fluids such as water. 9,18,19 Inclusion of viscosity is important for microscopic living cells suspended in water or salt solutions, such as those in flow cytometry, especially when describing the speed of particle drift and the optimal frequencies for cell sorting.…”

Cylindrical Piezoelectric PZT Transducers for Sensing and Actuation

“…However, limited literature has investigated the use of cylindrical ultrasound transducers for particle separation. A cylindrical PZT-4 transducer with an outer diameter of 19 mm, inner diameter of 16 mm and length of 28 mm was employed for separating microparticles in a continuous flow system [ 38 ]. A water-based and a blood-resembling fluid were considered in the study.…”

When Bubbles Are Not Spherical: Artificial Intelligence Analysis of Ultrasonic Cavitation Bubbles in Solutions of Varying Concentrations

“…Acoustic treatment of liquids is widely used for such purposes as aeration, vibration-induced phase separation, and acoustic spectral analysis of a fluid in a flow. − During ultrasonic acoustic cavitation, small bubbles in liquid are produced by propagating high-frequency pressure fluctuations. − Newly nucleated bubbles undergo a certain evolution. They often tend to grow, while their size oscillates due to the acoustic excitation causing compressive and tensile stress.…”