The concept and design are really actually simple. You get a small generator from a rechargeable flashlight, rig it up so you can turn the generator axle when you step down, and channel that energy to a cell phone's (or other device's) charger cord. You can use this when you are jogging or walking or just when you're sitting down and feel like tapping your foot.
The materials are really pretty cheap and the project is easy to make. The only thing that you will have to adjust for is that you probable won't have the same kind of shoe I have. So you might need to make some adjustments, but the concept is still the same.
Step 1: Materials
Next, you'll need two rechargeable flashlights for their generators. The two pictured below are the two I used and the next picture is one of their generators. I got the flashlights from my local Radio Shack and the brand is MegaBrite.
The other materials are: a spring, some wood, a small piece of re-bar, some thick wire, some small screws, and a cell phone charger.
As far as tools go, you'll need some basic hand tools, a drill, a band saw (unless you want to do it by hand), and some electrical tape.
Step 2: Hollow Out the Shoe
Next, drill a hole in the back or side of the shoe. This is where your charger cord will go in and connect to the generators.
Step 3: Dissect Flashlights
Step 4: Front Assembly
Step 5: Connect the Axle
Next, connect the axle to the front assembly. You just need to slide it onto the generator assemblies. This will probably be easier if you put this on while you're putting together the front assembly.
Step 6: The Back Block
The front part will connect with the generator assemblies and the two tower-like appendages are for holding the spring.
Its not shown in the picture, but you will need to drill a hole in each tower so a wire will be able to pass through.
Step 7: The Spring
I started by cutting a small piece of re-bar and putting a hole in it. This will go in between the two towers of the back block and the wire will go through the hole. Then, I got a small spring and slid it over the re-bar.
Now the whole thing is ready to together and in the shoe.
Step 8: Putting It All Together
Next, cut the cord off of your cell-phone charger and split and strip the ends. Pass the cord through the back hole of the shoe and connect the charger wires to the generator wires. Finally, wrap the exposed part of the wires in electrical tape.
Now for the spring. Drill a hole on each side of the shoe, about where the holes in the towers are. Now pass a wire through the shoe, back block, and spring assembly. Then cut the wire on each side to about 1" and just fold it over.
All that is left now is connecting the rest of the lever.
Step 9: The Lever
Step 10: Fininishing Touches/ Conclusion
Just in case you're in doubt, the shoe really does create electricity. Even though it doesn't look very fancy, I think its pretty cool that you have an independent and green power source wherever you go. All you have to do is walk.
Again, you will probably have to make adjustments for you model because I doubt your shoe will be like mine, but it should be basically the same.
Good luck with your project and thanks for reading my Instructable.