Analysis of the particle stability in a new designed ultrasonic levitation device.

The use of acoustic levitation in the fields of analytical chemistry and in the containerless processing of materials requires a good stability of the levitated particle. However, spontaneous oscillations and rotation of the levitated particle have been reported in literature, which can reduce the applicability of the acoustic levitation technique. Aiming to reduce the particle oscillations, this paper presents the analysis of the particle stability in a new acoustic levitator device. The new acoustic levitator consists of a piezoelectric transducer with a concave radiating surface and a concave reflector. The analysis is conducted by determining numerically the axial and lateral forces that act on the levitated object and by measuring the oscillations of a sphere particle by a laser Doppler vibrometer. It is shown that the new levitator design allows to increase the lateral forces and reduce significantly the lateral oscillations of the levitated object.

[1]  T Laurell,et al.  Sample enrichment in a single levitated droplet for capillary electrophoresis. , 1998, Journal of chromatography. B, Biomedical sciences and applications.

[2]  J. Popp,et al.  Raman acoustic levitation spectroscopy of red blood cells and Plasmodium falciparum trophozoites. , 2007, Lab on a chip.

[3]  F. Buiochi,et al.  Finite element analysis and optimization of a single-axis acoustic levitator , 2010, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  Alexander Scheeline,et al.  Design and implementation of an efficient acoustically levitated drop reactor for in stillo measurements. , 2007, The Review of scientific instruments.

[5]  J. Gallego‐Juárez.  Piezoelectric ceramics and ultrasonic transducers , 1989 .

[6]  W. J. Xie,et al.  Parametric study of single-axis acoustic levitation , 2001 .

[7]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[8]  W. Xie,et al.  Dependence of acoustic levitation capabilities on geometric parameters. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[9]  A. Biswas.  Thermal Processing of o-Terphenyl: A Raman Study , 1993 .

[10]  E. Brandt.  Levitation in Physics , 1989, Science.

[11]  Staffan Nilsson,et al.  Airborne chemistry: acoustic levitation in chemical analysis , 2004, Analytical and bioanalytical chemistry.

[12]  T. Weigel,et al.  Raman spectroscopy on deformed droplets: theory and experiment , 2004 .

[13]  D. McNaughton,et al.  Chemical analysis of acoustically levitated drops by Raman spectroscopy , 2009, Analytical and bioanalytical chemistry.

[14]  Louis Vessot King,et al.  On the Acoustic Radiation Pressure on Spheres , 1934 .

[15]  Cameron Tropea,et al.  On the acoustic levitation of droplets , 1998, Journal of Fluid Mechanics.

[16]  Cameron Tropea,et al.  Flowfield characteristics of an aerodynamic acoustic levitator , 1997 .

[17]  E. Degerman,et al.  Airborne cell analysis. , 2000, Analytical chemistry.

[18]  Jonas Johansson,et al.  Airborne chemistry coupled to Raman spectroscopy. , 2003, Analytical chemistry.

[19]  Karl Bücks,et al.  Über einige Beobachtungen an schwingenden Piezoquarzen und ihrem Schallfeld , 1933 .

[20]  A. Biswas.  Solidification of acoustically levitated o-terphenyl crystals: a Raman study , 1995 .

[21]  C. A. Rey,et al.  Acoustic levitator for structure measurements on low temperature liquid droplets. , 2009, The Review of scientific instruments.

[22]  Robert E. Apfel,et al.  A novel multiple drop levitator for the study of drop arrays , 1996 .

[23]  M. Barmatz,et al.  Acoustic radiation potential on a sphere in plane, cylindrical, and spherical standing wave fields , 1985 .

[24]  Lawrence E. Kinsler,et al.  Fundamentals of acoustics , 1950 .

[25]  Athikom Bangviwat,et al.  Optimizing the performance of piezoelectric drivers that use stepped horns , 1991 .