Systems and methods for separating particles and/or substances from a sample fluid

A system for separating particles from a sample fluid, comprising:

• a chamber;
• a sample fluid inlet for introducing a sample fluid to the chamber;
• a buffer fluid inlet for introducing a buffer fluid to the chamber, wherein a simultaneously-introduced sample fluid and buffer fluid pass through the chamber such that a fluidic interface is formed between the sample fluid and the buffer fluid as the fluids pass through the chamber, the sample fluid having particles of a first characteristic and particles of a second characteristic therein;
• a mechanism for applying at least one of an electrophoretic and a dielectrophoretic force to the fluids for urging the particles of the first characteristic to pass through the interface into the buffer fluid;
• a mechanism for applying an acoustic force to the fluids for urging the particles of the second characteristic to remain in the sample fluid;
• a sample fluid outlet coupled to the chamber;
• and
• a buffer fluid outlet coupled to the chamber, the buffer fluid being substantially separated from the sample fluid;
• wherein the particles of the second characteristic substantially remain in the sample fluid during the separation.

A system for separating particles from a sample fluid, comprising:

• a chamber;
• a sample fluid inlet for introducing a sample fluid to the chamber;
• a buffer fluid inlet for introducing a buffer fluid to the chamber, wherein a simultaneously-introduced sample fluid and buffer fluid pass through the chamber such that a fluidic interface is formed between the sample fluid and the buffer fluid as the fluids pass through the chamber, the sample fluid having particles of a first characteristic and particles of a second characteristic therein;
• a mechanism for applying at least one of an electrophoretic and a dielectrophoretic force to the fluids for urging the particles of the first characteristic to pass through the interface into the buffer fluid;
• a mechanism for applying an acoustic force to the fluids for urging the particles of the second characteristic to remain in the sample fluid;
• a sample fluid outlet coupled to the chamber;
• a buffer fluid outlet coupled to the chamber, the buffer fluid being substantially separated from the sample fluid;
• and
• wherein the mechanism for applying the acoustic force to the fluids comprises:
• a wave emitter positioned on one side of the chamber for creating a standing wave that runs transversely across the chamber;
• an acoustic reflector positioned on a side of the chamber opposite the wave emitter;
• and
• wherein the mechanism for applying at least one of the electrophoretic force and the dielectrophoretic force comprises:
• a first electrode positioned a same side of the chamber as the wave emitter;
• and
• a second electrode positioned on the side of the chamber opposite wave emitter.

A method for separating particles from a sample fluid, comprising:

• simultaneously passing a sample fluid and a buffer fluid through a chamber such that a fluidic interface is formed between the sample fluid and the buffer fluid as the fluids pass through the chamber, the sample fluid having panicles of a first characteristic and particles of a second characteristic therein;
• applying at least one of an electrophoretic and a dielectrophoretic force to the fluids for urging the particles of the first characteristic to pass through the interface into the buffer fluid;
• applying an acoustic force to the fluids for urging the particles of the second characteristic to remain in the sample fluid;
• allowing a gravitational force to the fluids to urge the particles of the second characteristic to remain in the sample fluid;
• substantially separating the buffer fluid from the sample fluid;
• wherein the fluids pass through the chamber at about a same velocity as measured at the interface,
• wherein at least one of the particles of the first characteristic and the particles of the second characteristic are pathogens,
• wherein the particles of the second characteristic substantially remain in the sample fluid during the separation,
• wherein the sample fluid also includes other particles,
• wherein the particles of the first characteristic are associated with the other particles,
• wherein applying the acoustic force to the fluids substantially causes the particles of the first characteristic to dissociate from the other particles,
• wherein the other particles substantially remain in the sample fluid after applying the force to the fluids,
• wherein the second characteristic is selected from the group consisting of:
• a particle volume greater than the particle volume of the particles of the first characteristic, and a particle surface area greater than the particle surface area of the particles of the first characteristic,
• wherein the acoustic force is an ultrasonic force,
• wherein the ultrasonic force creates a transverse standing wave in the fluids, and
• wherein the transverse standing wave urges the particles of the second characteristic toward an acoustic pressure node in the sample fluid.