[marshray]

How small would you have to make one that could check the airflow caused by sound waves?

Could you make an array of them oriented perpendicular to the plane, like a sheet?

Could you make it light enough to float on sound?

What kinds of things might it be good for? Sound dampening?

Could a paddlewheel configuration extract energy from air or liquid flow in any direction?

[imperator]

The current use for Tesla Valves is in microfluidics. On the macro level, people generally use one way valves that have moving parts. To harness the flow of a fluid being acoustically pumped, I don't know what it would take.

You could make an array of them perpendicular to a plane. Perhaps, by etching them into silicon. On a macro scale, you could machine them with a CNC machine, or even with hand tools depending on your tolerances.

For sound, you energy density is rather low, so the material you wish to propel would have to be incredibly light. And you would probably have better luck trying to lift a plate of some super light material. The Tesla Valve is most useful as a device where you want to check the flow from moving one way.

Anywhere, where having a moving part is a pain in the butt, and you want a more robust system. When you're etching things into silicon, generally, you want to avoid have to make lots of tiny micromechanisms.

As a paddlewheel, it would probably not make sense to use the Tesla Valve. Turbines are well understood. If you want to make rotary motion, that's the way to go.