Some browsing lead me to this video
Sheet material flexures cut so that their spiral blade geometry twists into a 3d shape.
So there is a claim on the video that this can be used as a turbine and they show them in pairs.
I can see that one sheet, e.g one side of this mechanism might work, where the outside is twisted against the inside to form a turbine blade array effect… but how can two possibly work ?
Would the twin rotor blade elements be opposing in flow reaction direction?