Footwear energy harvesting system

1. A footwear energy harvesting system comprising:

a first chamber situated in footwear;

a second chamber situated in the footwear;

a pneumatic rectifier connected to the first and second chambers; and

a pneumatically drivable energy converter connected to an output of the pneumatic rectifier; and

wherein the first and second chambers are compressible and contain a gas, and the energy converter is driven by motion of the gas.

2. The system of claim 1 , wherein the pneumatic rectifier comprises:

a first valve having an input connected to an output of the first chamber and having an output;

a second valve having an output connected to an input port of the first chamber and having an input;

a third valve having an input connected to an output of the second chamber, and having an output; and

a fourth valve having an output connected to an input port of the second chamber, and having an input; and

wherein each valve permits flow only from the input to the output of the valve.

3. The system of claim 2 , wherein:

the energy converter has an input connected to the outputs of the first and third pneumatic valves; and

the energy converter has an output connected to the inputs of the second and fourth pneumatic valves.

4. The system of claim 1 , wherein the energy converter is a pneumatic-to-electrical converter.

5. The system of claim 4 , wherein pneumatic-to-electrical converter is connected to an electronic mechanism such as a cell telephone, a PDA, a portable computer, storage, a GPS device, body safety or navigation lights, instrumentation, or the like.

6. The system of claim 3 , wherein the energy converter is a pneumatically drivable pump or a pneumatically drivable massager.

7. The system of claim 3 , wherein an ambulatory movement of the footwear causes a pressure differential between the inputs and outputs of the first and second chambers to result in a flow through the energy converter via the input and the output of the converter.

8. The system of claim 1 , wherein the first and second chambers, the pneumatic rectifier, and the pneumatically drivable energy converter are pneumatically interconnected via a pneumatic path not open to the ambient atmosphere during operation.

9. The system of claim 1 , further comprising:

a pneumatically drivable pump connected to the first chamber, the second chamber, the pneumatic rectifier, and pneumatically drivable energy converter; and

a gas storage device connected to the pneumatically drivable pump;

wherein the pneumatically drivable pump moves gas to the gas storage device for storage under pressure.

10. A footwear energy harvesting system comprising:

a first compressible chamber situated in or proximal a sole of an article of footwear, the first compressible chamber including a first input tube and a first output tube;

a second compressible chamber situated in or proximal the sole of the article of footwear, the second compressible chamber including a second input tube and a second output tube;

a pneumatic rectifier connected to the first input tube, the second input tube, the first output tube, and the second output tube, wherein the pneumatic rectifier permits flow from the first output tube and the second output tube to a pneumatic rectifier output, but substantially not reverses of these flows, and wherein the pneumatic rectifier permits flow from a pneumatic rectifier input to the first input tube and the second input tube, but substantially not reverses of these flows; and

a pneumatically drivable energy converter connected to the pneumatic rectifier output and the pneumatic rectifier input; and

wherein the first and second compressible chambers, the pneumatic rectifier, the pneumatically driven energy converter, and interconnecting tubes contain a fluid, and the energy converter is driven by motion of the fluid induced as the first and second compressible chambers are compressed and expanded during walking of a wearer of the article of footwear.

11. The system of claim 10 , wherein the pneumatic rectifier comprises:

a first output valve connected to the first output tube;

a second output valve connected to the second output tube;

a first input valve connected to the first input tube; and

a second input valve connected to the second input tube;

wherein each valve is a one-way valve.

12. The system of claim 10 , wherein the fluid is a gas.

13. The system of claim 10 , wherein the pneumatically drivable energy converter is located not in the sole of the article of footwear.

14. The system of claim 13 , wherein the pneumatically drivable energy converter is located substantially above the sole of the article of footwear.

15. A footwear energy harvesting system comprising:

a first chamber situated in or proximal a sole of an article of footwear;

a second chamber situated in or proximal the sole of the article of footwear;

a pneumatic rectifier connected to the first and second chambers and having an output and an input; and

a pneumatically drivable energy converter connected to the output and the input of the pneumatic rectifier, the pneumatically drivable energy converter being disposed at a location in or proximal the article of footwear substantially above the sole of the article of footwear; and

wherein the first and second chambers are compressible and contain a fluid, and the energy converter is driven by motion of the fluid.

16. The system of claim 15 , wherein the fluid is a gas.

17. The system of claim 15 , wherein the fluid is a liquid.

18. The system of claim 15 , wherein the energy converter converts motion of the fluid to electrical energy.

19. The system of claim 15 , wherein the pneumatically drivable energy converter is located above the height of an ankle of a wearer of the article of footwear.

20. The system of claim 15 , wherein the pneumatically drivable energy converter is located in or on an upper portion of the article of footwear.