piezoelectric shoes: charge your mobile device by walking!

Note: This is my first note!
When you have a very important text to send, have you ever had such a moment, but your phone died before you finished sending it?
Almost anyone with a mobile phone/device has experienced such a frustrating moment that the device is unable to complete the task due to lack of energy.
My project aims to solve this problem by creating a shoe insole that converts the physical energy generated by walking into electrical energy and then stores it in a portable battery pack to promote health.
In this way, you will always have an emergency power supply (
You will also update some of your own body energy)!
The list below is divided into 2 categories.
The first class consists of what is needed to complete the project, while the other is made up of something very helpful.
Note: You can skip this step if you don\'t like to learn something very cool.
To fully understand the science behind this project, it is helpful to understand how it works.
Basically, the main power source that makes this project possible is the so-called piezoelectric sensor (
It\'s a bite, I know).
Piezoelectric sensors or piezoelectric elements consist of materials such as crystals and certain ceramics that have special properties that allow them to convert physical energy into AC electrical energy.
Fortunately, we can take advantage of this particular feature and place the piezoelectric element at our feet so that every time we take a step, we push the piezoelectric element with our weight
Then turn these energies into electricity.
However, the only problem is that we need DC instead of AC in order to power our stuff.
We can solve this problem by creating a bridge rectifier with diodes to convert the AC power supply to the DC power supply we can use.
We need a plastic base to make our piezoelectric generator.
I have provided a link to my tinkercad file below.
Depending on the size of your needs/feet, feel free to customize them.
The piezoelectric element holes are strategically placed so that they are aligned with the large dents on my shoe insole, indicating the area with the greatest pressure.
These files are based on my feet and this is the size of our 9th. 5 .
Although my heel fits perfectly, my toes need to be polished a little better in order for it to fit.
Piezoelectric shoe insole (toes)
Piezoelectric shoe insole (heel)
Once we have finished making the basics for our piezoelectric generators, it\'s time to glue them with heat.
I found that the best technique to glue the element to the board is to apply a thin layer of glue to the edge of the hole in the plastic, and then quickly press the piezoelectric element on the glue before the glue cools down.
Be careful not to apply too much glue or you may limit the foam pad (
It will stick to the top of the piezoelectric element)
Fully compressed.
Also, make sure that the glue does not cover the contact points of the black or red wires as we will Weld to these points soon.
Make sure you glue the piezoelectric elements on both sides of the plastic.
If you have a multimeter, you can ensure that the piezoelectric element works by setting the multimeter to AC voltage and pressing the piezoelectric element.
After sticking all the piezoelectric materials in the appropriate position, you can stick the foam/cardboard to each piezoelectric element.
While the piezoelectric elements produce a large amount of voltage, they do not produce a lot of amps.
We can solve this problem by wiring all piezoelectric components in parallel (
In other words, positive is always welded to each other, negative is always welded to each other).
In this way, we will be able to increase the number of amplifiers to charge our devices faster.
In order to prevent the wire from braking from the solder joint, use hot glue to fix a part of the wire in place so that the stress on the wire does not occur on the solder joint.
You can connect the piezoelectric elements from one side of the plastic by passing the wires of one piezoelectric element through the hole, so that they can weld the other side parallel to the piezoelectric element.
Once all the piezoelectric elements on the heel are wired in parallel, weld the last piezoelectric element on the chain to one of the piezoelectric elements on the toe and continue to weld the piezos in parallel, until all 14 elements are connected.
Note: You can skip this step if you already have a diode!
Don\'t be afraid if you have no diodes around like me!
You can find very good diodes in the old, bad CFL bulbs at home.
Note: The CFL bulb contains mercury and other toxic materials in its glass tube.
Don\'t break these pipes!
Build the bridge rectifier: OK, so for those who don\'t know how to read the circuit diagram, the 4 line segments with arrows on them represent the diode.
The arrow always points to the side of the marked diode, also known as the front.
If you have a small rectangular diode like me, there is no color mark on the front, but a very small marking/marking.
You should be able to create Bridge diodes by following this chart.
Wiring bridge rectifier: once we have completed the wiring of the piezoelectric generator, we can install it!
All you need to do is slide the plastic piezoelectric generator into the inside of the shoe and insert the original sole on it.
Place the previously connected USB cable between the tongue and the outside of the shoe as shown in the picture above.
To install the battery, stick it between the tongue of the shoe and the laces and tie the shoe tightly.
If you have velcro, I suggest you use it to better fix the battery pack to prevent it from falling off at runtime.
I also suggest you make a foam cut for the sole of your other shoe so that you can use it as a riser in your shoe with no generator inside.
I use my shoes that don\'t have a piezoelectric generator as a storage space for my mobile charging cable, so I will always have everything I need to charge.
Now that you have finished generating shoes, there is only one way to see how they work --EXERCISE!
By walking, hiking or exercising for a few hours, you should be able to charge your mobile device.
Keep in mind that your battery will only be charged when you take a step, so be on the battery for a while.