Fluid ejection with micropumps and pressure-difference based fluid flow

A fluid ejection device comprising:

• a plurality of nozzles;
• a plurality of ejection chambers, comprising a respective ejection chamber of the plurality of ejection chambers fluidically coupled to a respective nozzle of the plurality of nozzles;
• a plurality of inlet passages, comprising a respective inlet passage fluidically coupled to the respective ejection chamber;
• a plurality of outlet passages, comprising a respective outlet passage fluidically coupled to the respective ejection chamber;
• at least one input channel, the at least one input channel fluidically coupled to at least a subset of inlet passages of the plurality of inlet passages, the at least one input channel to supply fluid to the subset of inlet passages at a first pressure;
• an input regulator to generate the first pressure in the fluid at the at least one input channel;
• at least one output channel, the at least one output channel fluidically coupled to at least a subset of outlet passages of the plurality of outlet passages, the at least one output channel to receive fluid from the subset of outlet passages at a second pressure different than the first pressure to thereby facilitate fluid circulation through ejection chambers fluidically coupled to the subset of inlet passages and the subset of outlet passages;
• an output regulator to generate the second pressure in the fluid at the at least one output channel;
• and
• at least one micropump fluidically coupled to at least one ejection chamber to pump fluid through the at least one ejection chamber.

A method, comprising:

• circulating fluid through a plurality of ejection chambers at a first flow rate by:
• supplying fluid to the plurality of ejection chambers at a first pressure;
• and
• collecting fluid from the plurality of ejection chambers at a second pressure that is lower than the first pressure;
• and
• compensate for pressure non-uniformities across the plurality of ejection chambers by selectively adjusting circulation of fluid through at least one ejection chamber to a second flow rate by actuating at least one micropump fluidically coupled to the at least one ejection chamber.