The dried grounds were sifted with a standard kitchen strainer to remove large clumps and then mixed with xanthan gum and carboxymethyl cellulose powders, which serve a similar purpose to binders, stabilizers, and thickeners.

Yeah, so don’t throw out those used coffee grounds, just mix them with the carboxymethyl cellulose powder you probably have in the cupboard, and the leftover xantham gum you have laying around.

Then make a custom syringe feeder for your 3d printer.

Meh. Easier to put them on my grass and fertilize the soil.