Systems and methods for tagging and acoustically characterizing containers

A system for acoustically ejecting fluid droplets, comprising:

• a plurality of containers comprising wells in a multi-well plate fabricated from a multi-cavity mold, each container housing a fluid with a surface exposed to air and having a container bottom with an acoustically readable tag embedded therein that identifies the container and acoustic impedance Z3 of the container bottom, the container bottom further having an upper surface in contact with the fluid and a lower surface in acoustic coupling relationship with respect to an acoustic transducer by means of an acoustic coupling fluid provided therebetween, the acoustic transducer having a known acoustic impedance Z1, the acoustic coupling fluid having a known acoustic impedance Z2, and each fluid having an unknown acoustic impedance Z4;
• in each container, a first interface between the acoustic coupling fluid and the lower surface of the container bottom;
• a second interface between the upper surface of the container bottom and the fluid therein;
• and a third interface between the surface of the fluid and the air;
• wherein the acoustic transducer is capable of (i) transmitting a first acoustic signal toward the container bottom, (ii) receiving reflections of the first acoustic signal generated at the first interface, at the second interface, and at the third interface, and (iii) transmitting a second acoustic signal through the container bottom into the fluid to acoustically eject a droplet of the fluid from the container;
• a controller comprising a processor and a computer readable medium with software algorithms stored thereon for characterizing the acoustic impedance Z3 of each container bottom and therefore the acoustic impedance Z4 of the fluid therein based on based on Z1, Z2, Z3, and the reflections at the first interface, the second interface, and the third interface, wherein Z4 enables proper selection of acoustic ejection parameters for the second acoustic signal.

A method for acoustically ejecting fluid droplets, comprising:

• providing a fluid container housing a fluid with a surface exposed to air and having a container bottom with an acoustically readable tag embedded therein that identifies the container and acoustic impedance Z3 of the container bottom, the container bottom further having an upper surface in contact with the fluid and a lower surface in acoustic coupling relationship with respect to an acoustic transducer by means of an acoustic coupling fluid provided therebetween, the acoustic transducer having a known acoustic impedance Z1, the acoustic coupling fluid having a known acoustic impedance Z2, and the fluid having an unknown acoustic impedance Z4, wherein a first interface is provided between the acoustic coupling fluid and the lower surface of the container bottom, a second interface is provided between the upper surface of the container bottom and the fluid, and a third interface is provided between the surface of the fluid and the air, and further wherein the acoustic transducer is capable of (i) transmitting a first acoustic signal toward the container bottom, (ii) receiving reflections of the first acoustic signal generated at the first interface, at the second interface, and at the third interface, and (iii) transmitting a second acoustic signal through the container bottom into the fluid to acoustically eject a droplet of the fluid from the container;
• transmitting the first acoustic signal toward the container bottom;
• receiving reflections of the first acoustic signal generated at the first interface, at the second interface, and at the third interface;
• using a controller comprising a processor and a computer readable medium with software algorithms stored thereon, characterizing the acoustic impedance Z4 of the fluid based on Z1, Z2, Z3, and the reflections at the first interface, the second interface, and the third interface;
• selecting acoustic ejection parameters for the second acoustic signal from Z4;
• and
• transmitting the second acoustic signal toward the container bottom with the selected acoustic ejection parameters to acoustically eject a fluid droplet from the fluid container.