US Patent 7560856 Harvesting energy from flowing fluid

Electrical energy is produced at a remote or close site by converting kinetic energy from fluid flow with membranes that generates electrical energy in response to deformation by the fluid flow passing though a piezo electric medium attached to the deforming membranes. Sets of membranes define variable fluid flow restrictors that oscillate due to interaction of the force of fluid flow and Bernoulli Effect. The device can be tuned to different flow regimes in order to enhance energy conversion efficiency. Each membrane may include one or more layers of piezoelectric material separated by insulating/stiffening layers. Further, the device may be mounted in a secondary flow path such as a side package or annular tube.