Remember that physics lab when you had to make standing waves with a Slinky and a jump rope in the school hallway? Change the slinky to a 3-D sound wave and you can pretty much visualize what’s happening here. The wave effectively becomes a surface which can support weight – and be moved.
Imagine touch free assembly of intricate assemblies. The Japanese who discovered this phenomena are doing just that.
So what happens if it’s in a liquid? Zero gravity? How strong is a surface of sound? Curious.