An articulated apparatus, comprising: a central core member; a plurality of transducers, wherein each of the plurality of transducers is connected at a first position to an outer surface of the central core member and at a second position to at least one of a plurality of flexible article disposed in contact with a fluid, characterised in that: each of the plurality of flexible articles has at least one contact surface permanently configured with at least one persistent deformation projecting transverse to a central axis of the central core member and maintained via at least one restraining component. undulations of the at least one persistent deformation corresponding to excitations of the plurality of transducers, each transducer is comprised of electroactive material, and the apparatus further comprises a generator control circuit coupled to the plurality of transducers, wherein undulations of the persistent deformations are induced by the flowing of the fluid and wherein the undulations of the persistent deformations induce the excitations in the plurality of transducers to drive the generator control circuit. a central core member; a plurality of transducers, wherein each of the plurality of transducers is connected at a first position to an outer surface of the central core member and at a second position to at least one of a plurality of flexible article disposed in contact with a fluid, characterised in that: each of the plurality of flexible articles has at least one contact surface permanently configured with at least one persistent deformation projecting transverse to a central axis of the central core member and maintained via at least one restraining component. undulations of the at least one persistent deformation corresponding to excitations of the plurality of transducers, each transducer is comprised of electroactive material, and the apparatus further comprises a generator control circuit coupled to the plurality of transducers, wherein undulations of the persistent deformations are induced by the flowing of the fluid and wherein the undulations of the persistent deformations induce the excitations in the plurality of transducers to drive the generator control circuit. wherein each of the plurality of transducers is connected at a first position to an outer surface of the central core member and at a second position to at least one of a plurality of flexible article disposed in contact with a fluid, characterised in that: each of the plurality of flexible articles has at least one contact surface permanently configured with at least one persistent deformation projecting transverse to a central axis of the central core member and maintained via at least one restraining component. undulations of the at least one persistent deformation corresponding to excitations of the plurality of transducers, each transducer is comprised of electroactive material, and the apparatus further comprises a generator control circuit coupled to the plurality of transducers, each of the plurality of flexible articles has at least one contact surface permanently configured with at least one persistent deformation projecting transverse to a central axis of the central core member and maintained via at least one restraining component. undulations of the at least one persistent deformation corresponding to excitations of the plurality of transducers, each transducer is comprised of electroactive material, and the apparatus further comprises a generator control circuit coupled to the plurality of transducers, wherein undulations of the persistent deformations are induced by the flowing of the fluid and wherein the undulations of the persistent deformations induce the excitations in the plurality of transducers to drive the generator control circuit.