US Patent 11557985 Piezoelectric and magnetostrictive energy harvesting with pipe-in-pipe structure

An apparatus includes an outer structure body having an inner surface defining a cavity and an inner structure body rotatably supported within the cavity. The inner structure body has an outer surface in opposing relation to the inner surface and a central bore. Movable elements are positioned along the inner surface and movably coupled to the outer structure body. Ball elements are positioned along the outer surface and coupled to the inner structure body for movement with the inner structure body. The ball elements releasably contact the movable elements and impart motion to the movable elements in response to relative motion between the inner structure body and the outer structure body. Energy harvesters are positioned to generate electrical charges based on piezoelectric effect or magnetostrictive effect when motion is imparted to the movable elements by the ball elements.