Finite element analysis and optimization of a single-axis acoustic levitator

A finite element analysis and a parametric optimization of single-axis acoustic levitators are presented. The finite element method is used to simulate a levitator consisting of a Langevin ultrasonic transducer with a plane radiating surface and a plane reflector. The transducer electrical impedance, the transducer face displacement, and the acoustic radiation potential that acts on small spheres are determined by the finite element method. The numerical electrical impedance is compared with that acquired experimentally by an impedance analyzer, and the predicted displacement is compared with that obtained by a fiber-optic vibration sensor. The numerical acoustic radiation potential is verified experimentally by placing small spheres in the levitator. The same procedure is used to optimize a levitator consisting of a curved reflector and a concave-faced transducer. The numerical results show that the acoustic radiation force in the new levitator is enhanced 604 times compared with the levitator consisting of a plane transducer and a plane reflector. The optimized levitator is able to levitate 3, 2.5-mm diameter steel spheres with a power consumption of only 0.9 W.

[1]  Arthur Ashkin,et al.  Optical Levitation by Radiation Pressure , 1971 .

[2]  Teruyuki Kozuka,et al.  Acoustic Standing-Wave Field for Manipulation in Air , 2008 .

[3]  E. H. Trinh,et al.  Compact acoustic levitation device for studies in fluid dynamics and material science in the laboratory and microgravity , 1985 .

[4]  E. Brandt,et al.  Acoustic physics: Suspended by sound , 2001, Nature.

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

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

[7]  Bernd Neidhart,et al.  Formation and growth of ice particles in stationary ultrasonic fields , 1998 .

[8]  Won-Kyu Rhim,et al.  An electrostatic levitator for high-temperature containerless materials processing in 1-g , 1993 .

[9]  W. J. Xie,et al.  Acoustic method for levitation of small living animals , 2006 .

[10]  S. Bauerecker,et al.  Trapping of heavy gases in stationary ultrasonic fields , 2002 .

[11]  R. Glynn Holt,et al.  A new method for measuring liquid surface tension with acoustic levitation , 1995 .

[12]  S. Bauerecker,et al.  Cold Gas Traps for Ice Particle Formation , 1998, Science.

[13]  A. Rulison,et al.  Electrostatic containerless processing system , 1997 .

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

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

[16]  A. Geim,et al.  Magnet levitation at your fingertips , 1999, Nature.

[17]  L. Gor’kov,et al.  On the forces acting on a small particle in an acoustical field in an ideal fluid , 1962 .

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

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

[20]  J A Gallego-Juarez.  Piezoelectric ceramics and ultrasonic transducers , 1992 .