10x Genomics (https://www.10xgenomics.com/) is the biggest company building the machines for this. They're publicly traded.
Microfluidics is being used in large scales in biological labs for sample analysis etc., so yes, there are practical applications but none that any random household needs or could even make any use of :)
Aside from these, it sounds like they will become lab tools not the Theranos-style lab replacements.
See:
One of the bigger hits was Berkeley Lights, a big deal in early cell line development for monoclonal antibodies: https://www.berkeleylights.com/technology/
But there’s be numerous others. All have advanced state of the art. But as another commenter said, not much for home use. Just industry.
If you want to play around with digital microfluids at home, check out the OpenDrop from gaudi.ch (http://www.gaudi.ch/OpenDrop/). I haven't played around with it yet, as I haven't found a practical use of this.
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