Microfluidic systems for particle trapping and separation using cavity acoustic transducers

A system for manipulating particles in fluids, the system comprising:

• an acoustic energy source configured to produce ultrasound;
• a device disposed over the acoustic energy source and comprising:
• a first channel;
• a first inlet into the first channel, wherein a volume of liquid that is received via the first inlet flows in a direction through the first channel;
• a first plurality of gas-liquid cavity acoustic transducers (CATs) lining a first side of the first channel, wherein each CAT of the first plurality of CATs is connected to the first channel at an angle so that a respective opening of each CAT of the first plurality of CATs faces toward the direction of flow of the volume of liquid through the first channel;
• and
• a second plurality of CATs lining a second side of the first channel, wherein the second side is opposite the first side, wherein each CAT of the second plurality of CATs is connected to the first channel at an angle so that a respective opening of each CAT of the second plurality of CATs faces away from the direction of flow of the volume of liquid through the first channel;
• wherein for each CAT of the first and second pluralities of CATs, a gas-liquid interface is created between the volume of liquid flowing through the first channel and a respective first volume of gas in the CAT, wherein the ultrasound produced from the acoustic energy source causes the gas-liquid interface to oscillate, thereby generating a plurality of micro-vortices in the first channel,
• wherein a plurality of particles in the volume of liquid are separated from the volume of liquid as the volume of liquid flows through the first channel, and
• wherein the plurality of particles separated from the volume of liquid are trapped in the plurality of micro-vortices.