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.

Disclosed are devices and methods for generating electrical power by using airflow energy to create air pressure fluctuations within Helmholtz chambers containing piezoelectric materials. The generator device includes an intake having stationary blades for directing wind into a flow treatment stage, which in turn directs a flow of modified air into a flow interface stage. In the flow interface stage, a plurality of Helmholtz chambers containing piezoelectric units are configured around a flow interface chamber wherein passing modified airflow establishes air pressure fluctuations within the Helmholtz chambers thereby causing the piezoelectric units to generate electricity. The device routes generated electrical current to a processor for use as a power source. Also disclosed is a method of generating electrical power using airflow energy. The method includes collecting airflow from the environment to create pressure fluctuations within containers housing piezoelectric units.

A box-type wind power generation device and a power generation device set is provided, the box-type wind power generation device includes a box body, a first energy collecting unit and a first connection member. The box body includes at least one flexible housing member and at least one rigid housing member which enclose at least one sealed cavity. The first energy collecting unit includes a piezoelectric membrane and electrodes deposited on both sides of the piezoelectric membrane, respectively; the first energy collecting unit overlying on an inner wall of the flexible housing member and are located in the sealed cavity. An end of the first connection member is fixed to the flexible housing member so that the first connection member is connected to the box body and at least a part of the first connection member is located outside the sealed cavity.

A vibration power generation device that further improves power generation efficiency includes a vibration exciting body in which vibration is caused by a flowing fluid, a vibrated body that is oscillatable and connected to the vibration exciting body, and a power generator to generate electricity by oscillation of the vibrated body. The vibration exciting body is in proximity to a wall surface, and vibration is caused in the vibration exciting body by a fluid flowing along the wall surface.

A funnel-shaped underwater energy harvesting equipment includes a piezoelectric element configured to be installed at a seabed and to be moved by a fluid in order to convert vibration energy into electricity. The funnel-shaped underwater energy harvesting equipment further includes a fluid collector coupled to the piezoelectric element and configured to increase velocity of the fluid flowing toward the piezoelectric element. The harvesting equipment exhibits improved energy conversion efficiency, while simplifying the shape of the harvesting equipment.

A vortex-induced vibration wind energy harvesting device, including an array consisting of a plurality of oscillators and a plurality of piezoelectric microelectromechanical systems (MEMSs), is provided. An oscillator is mounted on each of the piezoelectric MEMSs. When any one of the oscillators is oscillated by and resonant with vortex shedding due to an incoming airflow, its vortices in the wake will enhance the oscillation of the downstream oscillators, so that overall oscillation of the oscillators in the array is strengthened. The piezoelectric MEMSs are deformed by the vibration of these oscillators to generate voltage and current to output. In the present invention, the oscillators are arranged closely. When the airflow passes the array, even weak airflow can generate periodic force and cause significant oscillation due to resonance. The MEMS can convert mechanical energy into electrical energy and output it in order to achieve the purpose of wind energy harvesting.

A hydroelectric system comprising a pipe from a water source at a high elevation which is made to open into a pressurized water filled chamber at a much lower elevation. The chamber contains a waterproofed piezoelectric element and waterproofed electric leads connected to the electric grid. The inlet pipe is divided into several pipes before being made to operatively connect to the chamber. Each of the several inlet pipes have their water flow regulated by a solenoid operated valve. Corresponding solenoid operated outlet valves are also provided. A rotary electric switch is also provided so as the switch arm is rotated the inlet and outlet valves are opened and closed in succession, causing waves of pressure on said piezoelectric material to produce electric power.

A piezoelectric power generation system includes a housing defining an opening therethrough and a support structure disposed within the housing, the support structure comprising a plurality of portions. The piezoelectric power generation system also includes one or more piezoelectric elements disposed between two of the plurality of portions of the support structure within the housing. Movement or vibration in the support structure compresses the one or more piezoelectric elements, wherein the one or more piezoelectric elements generate electric energy when compressed. The piezoelectric power generation system further includes one or more exciters coupled to the support structure, wherein the exciters move or vibrate when acted on by a flow of fluid, wherein the motion of vibration of the one or more exciters is translated to the support structure and ultimately to the one or more piezoelectric elements.

A piezoelectric power generation device includes a stator, a rotor, and one or more piezoelectric power generation elements. The stator comprises an internal surface which defines an internal orifice. The one or more piezoelectric power generation elements are disposed on the internal surface of the stator. The rotor is disposed within the internal orifice comprising one or more lobes formed on an outside surface of the rotor. The rotor is configured to rotate with respect to the stator and the one or more piezoelectric power generation elements. The one or more lobes contact the one or more piezoelectric power generation elements as the one or more lobes rotate past the one or more piezoelectric power generation elements. The one or more piezoelectric power generation elements generate energy when contacted by the one or more lobes.

In various embodiments, a device for determining a property of a fluid may be provided. The device may include a fluid receiving structure configured to receive the fluid having a first condition. The device may further include a flow control structure coupled to the fluid receiving structure. The flow control structure may be configured to change the first condition of the fluid to a second condition. The device may further include a determination mechanism configured to determine the property of the fluid based on the second condition. The device may also include a voltage generation mechanism a voltage generation mechanism configured to generate a voltage based on the second condition.