Acoustic system for material transport

A method for moving an acoustically positioned object within a chamber, comprising:

• applying acoustic energy of first and second resonant modes along the same direction within said chamber, said first and second modes having first and second pressure wells, respectively, that are widely spaced apart;
• and
• introducing an object into the region within said chamber which extends between said first and second pressure wells;
• said step of applying including varying the relative intensities of said first and second modes to control the relative distances of said object from said first and second pressure wells while said object lies in said region.

Apparatus for controlling movement of an object, comprising:

• walls forming a chamber of predetermined dimensions;
• and
• transducer means for applying acoustic energy of a plurality of frequencies to said chamber, said frequencies chosen which are resonant to the chamber dimensions to levitate an object within the chamber;
• said transducer means including means for simultaneously applying two different frequencies which are each resonant to the same chamber dimension but which have pressure wells that are spaced apart, and means for varying the relative intensities of the two different frequencies to control the relative distances from the pressure wells of an object lying between the two pressure wells.

Apparatus for applying acoustic energy to an object comprising:

• walls forming a chamber having a width and length and having first and second ends separated by said length;
• and
• transducer means for applying acoustic energy to said chamber of a plurality of different frequencies that produce wavelengths that are resonant to different corresponding dimensions of said chamber, including the width and length thereof, said transducer means applying all of said acoustic energy to said first end of said chamber;
• said transducer means including a plurality of transducers, each including a transducer element, a tube extending from said element to said chamber, and means for generating an element driving current of predetermined frequency, which produces a predetermined wavelength in said tube, said tube having a length equal to a whole number of half wavelengths of said predetermined wavelength.

Apparatus for controlling movement of an object, comprising:

• walls forming a chamber of predetermined dimensions;
• and
• transducer means for applying acoustic energy of a plurality of frequencies to said chamber, said frequencies chosen which are resonant to the chamber dimensions to levitate an object within the chamber;
• said transducer means including means for switching between a plurality of frequencies which are each resonant to a first chamber dimension, to move the object between pressure wells formed by the different resonant frequencies;
• said plurality of frequencies including a first frequency which produces a first pressure well at the center of said chamber along said first chamber dimension, and a second frequency which produces a pair of pressure wells lying respectively on initial and final sides of said first pressure well;
• and also including
• means for detecting the passage of an object past said first pressure well, for operating said switching means to switch from said first frequency to said second frequency.

Apparatus for controlling movement of an object, comprising:

• walls forming a chamber of predetermined dimensions;
• and
• transducer means for applying acoustic energy of a plurality of frequencies to said chamber, said frequencies chosen which are resonant to the chamber dimensions to levitate an object within the chamber;
• said transducer means including means for switching between a plurality of frequencies which are each resonant to a first chamber dimension, to move the object between pressure wells formed by the different resonant frequencies;
• said chamber having a length forming said first chamber dimension, and having first and second end portions spaced along said length dimension;
• said frequencies which are each resonant to said first chamber dimension including a first frequency which produces a first pressure well at the center of the chamber length and a second frequency which produces second pressure wells located at said opposite end portions of said chamber;
• and including
• walls forming an access opening at said first end portion of said chamber, to permit the introduction of an object near the second pressure well which lies at said first end portion of the chamber;
• and
• means for applying heat to said second end portion of said chamber, to heat the object when it has been moved thereto.