초록 ▼

An acoustic standing wave is established in a fluid medium with a varying energy density in its nodal planes. Particles in the fluid medium responsive to the acoustic energy accumulate at these nodal planes and by the action of the variations of energy density in conjunction with the fluid viscous f

An acoustic standing wave is established in a fluid medium with a varying energy density in its nodal planes. Particles in the fluid medium responsive to the acoustic energy accumulate at these nodal planes and by the action of the variations of energy density in conjunction with the fluid viscous forces and/or field forces acting in the direction of the nodal planes, the movement of the particles held at these planes can be controlled. The adverse effects of attenuation of the acoustic beams producing the standing wave are reduced in this system, because any streaming due to imbalance of the acoustic forces forming the standing wave does not act in the direction in which the movement of the particles can be controlled.

대표청구항 ▼

A method of manipulating particles in a fluid medium, comprising the steps of: (a) injecting ultrasonic energy into a fluid medium and establishing an ultrasonic standing wave in the medium; (b) choosing standing wave characteristics of said standing wave in relation to the particles so as to accumu

A method of manipulating particles in a fluid medium, comprising the steps of: (a) injecting ultrasonic energy into a fluid medium and establishing an ultrasonic standing wave in the medium; (b) choosing standing wave characteristics of said standing wave in relation to the particles so as to accumulate at least a portion of the particles at least at one nodal plane of the standing wave in the fluid medium; (c) giving a varying spatial energy density distribution to said standing wave in at least one of its at least one nodal planes in the fluid medium; and (d) controlling positions of the particles in said at least one nodal plane by the varying energy density of the standing wave in each said at least one nodal plane.