Acoustic levitation with self-adaptive flexible reflectors

Abstract

Two kinds of flexible reflectors are proposed and examined in this paper to improve the stability of single-axis acoustic levitator, especially in the case of levitating high-density and high-temperature samples. One kind is those with a deformable reflecting surface, and the other kind is those with an elastic support, both of which are self-adaptive to the change of acoustic radiation pressure. High-density materials such as iridium (density 22.6 gcm(-3)) are stably levitated at room temperature with a soft reflector made of colloid as well as a rigid reflector supported by a spring. In addition, the containerless melting and solidification of binary In-Bi eutectic alloy (melting point 345.8 K) and ternary Ag-Cu-Ge eutectic alloy (melting point 812 K) are successfully achieved by applying the elastically supported reflector with the assistance of a laser beam.

Measurement and simulation of acoustic radiation force on a planar reflector

“…This is the essential mechanism of almost all the acoustic radiation phenomena. [1][2][3][4][5][6][7] However, it is still not easy to accurately calculate the acoustic radiation pressure, mainly because the phenomenon is a complex nonlinear effect. [8][9][10][11][12][13] This kind of nonlinear problem can be processed approximately.…”

Morphing Surfaces Enable Acoustophoretic Contactless Transport of Ultrahigh-Density Matter in Air

“…For such a soft reflector, a more detailed model is needed. Indeed, the contribution of the surface tension and the hydrostatic load of the liquid layer play an important role for low tension of the membrane 23 .…”

“…The deformation changes in turn the acoustic resonance frequency of the acoustic levitator, modifying the acoustic field: the steady-state nature of the radiation pressure couples with the reaction forces of the reflecting material. The first application of this phenomenon to trap heavy samples in an axisymmetric levitator has been qualitatively reported by Hong et al 23 .…”

Surface wave patterns on acoustically levitated viscous liquid alloys

“…9 Its sound emitter vibrates sinusoidally with a frequency of 20 kHz. At first, the samples of binary In-33.3%Bi eutectic alloy and ternary Ag-25.5%Cu-24.5%Ge eutectic alloy were prepared by 99.99% pure metals.…”