Acoustic perfusion devices

A method for separating biological cells from a fluid mixture, comprising:

• flowing the fluid mixture containing the biological cells through an acoustic perfusion device, the device comprising:
• an acoustic chamber;
• an inlet port, an inlet flow path leading from the inlet port to the acoustic chamber;
• an outlet port for recirculating the fluid mixture and the biological cells;
• at least one collection port for collecting harvest fluid;
• and
• at least one ultrasonic transducer below the at least one collection port and at least one reflector opposite the at least one ultrasonic transducer, wherein the at least one ultrasonic transducer includes a piezoelectric material driven by a voltage signal to create a first multi-dimensional acoustic standing wave across a collection flow path leading from the acoustic chamber to the at least one collection port;
• and
• a secondary flow chamber in which the harvest fluid passes through a second acoustic standing wave with a frequency different from or equal to the first multi-dimensional acoustic standing wave to further clarify the harvest fluid;
• driving the at least one ultrasonic transducer to create the acoustic standing wave;
• and
• collecting a fluid mixture enriched in cells from the outlet port and collecting a harvest fluid mixture depleted in cells from the at least one collection port.

A flow device, comprising:

• at least one inlet for receiving a flowing mixture of a primary fluid and cells,
• a first ultrasonic transducer configured to produce a first multi-dimensional acoustic standing wave and a pressure rise and an acoustic radiation force on cells, generated at an upstream interface region of the first multi-dimensional acoustic standing wave, to separate the flowing mixture into a primary high cell concentration fluid stream and a secondary harvest fluid stream;
• an outlet port for the primary high cell concentration fluid stream;
• a bleed port for extracting a concentrated fluid/cell mixture;
• and
• at least one collection port for the secondary harvest fluid stream;
• and
• a secondary flow chamber containing a second ultrasonic transducer that produces a second acoustic standing wave with a frequency different from or equal to the first multi-dimensional acoustic standing wave to further clarify the secondary harvest fluid stream.