Acoustic droplet ejection of non-newtonian fluids

A droplet ejection system configured to eject a droplet from a non-Newtonian fluid in a reservoir, the system comprising:

• an acoustic ejector configured to:
• emit focused acoustic energy in a first pattern comprising a first tone burst segment to a fluid surface of the non-Newtonian fluid to generate a leading lobe and a filament from the fluid surface without separating the filament from the leading lobe or the fluid surface, wherein a diameter of the leading lobe is greater than a diameter of the filament;
• and
• emit focused acoustic energy in a second pattern comprising a second tone burst segment and a third tone burst segment to the leading lobe to separate the leading lobe from the filament without ejecting satellite droplets such that the filament retreats into the fluid surface, wherein an amplitude of the focused acoustic energy varies between the first tone burst segment and the second tone burst segment or the second tone burst segment and the third tone burst segment;
• and
• a processor and memory device storing executable instructions that, when executed by the processor, cause the acoustic ejector to emit the focused acoustic energy in the first pattern to a fluid surface of the non-Newtonian fluid and emit focused acoustic energy in the second pattern to the leading lobe, wherein each of the first tone burst segment and the third tone burst segment include a plurality of cycles of waveform.

A method of ejecting a droplet containing a non-Newtonian fluid from a fluid reservoir, the method comprising:

• emitting a tone burst pattern of focused acoustic energy to a fluid reservoir containing a non-Newtonian fluid, wherein the emission of the tone burst pattern to the fluid reservoir ejects a droplet of the non-Newtonian fluid from the fluid reservoir, and wherein the tone burst pattern comprises:
• a first discrete tone burst segment configured to generate a leading lobe and a filament from a fluid surface of the fluid reservoir without separating the filament from the leading lobe or the fluid surface, wherein a diameter of the leading lobe is greater than a diameter of the filament;
• a second discrete tone burst segment emitted subsequent to the first discrete tone burst segment;
• and
• a third discrete tone burst segment emitted subsequent to the second discrete tone burst segment, wherein an amplitude of the focused acoustic energy varies between the first discrete tone burst segment and the second discrete tone burst segment or the second discrete tone burst segment and the third discrete tone burst segment, wherein each of the first discrete tone burst segment and the third discrete tone burst segment include a plurality of cycles of waveform.