Here's a link to mat hydroponics. There's another link within the body of this link that is a You-Tube video; well worth the watch!

Here is a link that might be useful: Microgreens: Mat Hydroponics

Yep, for microgreens you're going to want to stay away from many of the traditional hydroponic methods. Anything with a single plant per spot concept isn't going to have the growing density you need.

You're looking for something that maximizes the growing surface area, like mat hydroponics. Wool felt, burlap, most any cloth-type growing surface will work. Sow your seeds right on the surface, roots go down, plants go up, voila! Plant at least twice as dense as you think you'd need, so that you account for potential germination failures and you can thin them as they grow.

Waterfall mat hydroponics. Use strips of rockwool mat or even human hair mat (you can find it) and build a vertical wall, have the roots hang down the back and let hyper-oxygenated nutrient water drrbble over the roots from a soaker hose up top and drip back into the open-top reservoir. Small floorprint required compared to a traditional horizontal table, works great with T5HO lighting. Only need two pumps, one air, one water. This makes a great microgreen perpetual harvest, especially for things like chives, catnip, wheat grass, etc.