Investigation of a line-focused acoustic levitation for contactless transport of particles

Abstract

We investigate herein an interesting acoustic line-focused levitation mechanism, enabling the simultaneous transportation of the acoustically levitated particles. It is shown that the performance of such a system is strongly dependent on the envelope of geometric parameters of the levitator. To study this dependence systematically, a thorough numerical model using the finite element method is developed. Both rigid and flexural radiating plates are considered. The effect of all important geometric parameters on the resulting acoustic potential patterns is investigated. After successful experimental validation, in which particles of density ca. 1000 times higher than that of their surrounding gas (∼1 g/cm3 versus ∼10−3 g/cm3) are levitated and translated, the model proves to be reliable in predicting the position as well as the force exerted on the levitated particles.

On the acoustic levitation stability behaviour of spherical and ellipsoidal particles

“…Owing to its material independency, acoustic levitation has found a wide spectrum of applications in contactless processing and analysis of liquid samples (Trinh, Thiessen & Holt 1998;Yarin, Pfaffenlehner & Tropea 1998). The contactless manipulation and transportation of particles and droplets is one of the most interesting challenges in the acoustic levitation field (Koyama & Nakamura 2010;Foresti et al 2011;Foresti, Nabavi & Poulikakos 2012) with applications ranging from the handling of living cells in lab-on-a-chip devices (Bruus et al 2011) to millimetre-size sample manipulations in air (Bjelobrk et al 2010).…”

Contactless transport of matter in the first five resonance modes of a line-focused acoustic manipulator

“…We were able to simultaneously levitate and transport solid particles of water-like density in air ($1 g/cm 3 vs. $10 À3 g/cm 3 ) with a travelling length of 37 mm (37 times the particle diameter) using a radiating plate oscillating at its second flexural mode. In another study, 28 we have investigated the effects of geometrical parameters, such as the length and width of the radiating plate, the radius and the width of the reflector, and the distance between the reflector and the radiating plate, on the acoustic potential field. In our previous works, 27,28 we focused our research on the first resonant mode (H 1 ), to achieve the highest levitation force.…”

Time-averaged acoustic forces acting on a rigid sphere within a wide range of radii in an axisymmetric levitator

“…Although the contactless manipulation and transportation of particles is one of the most interesting challenges in the acoustic levitation field [4][5][6], the most common acoustic levitator deployed in laboratory and studied in literature is the axisymmetric levitator. Study of axisymmetric levitator has been conducted by means of analytical solutions or numerical methods (Finite Element, Boundary Element, Rayleigh formula) but always with the assumption of ideal fluid [7][8][9][10][11].…”