1)First,we traced out the circumference of the piezo disc on the back and the front of the sole of a shoe using a marker.We put about 3 piezo discs on the back of the sole and 2 piezo discs on the front of the sole.
2)Next using the compass draw a circle with a radius that is 2mm smaller than that of the piezo discs’ outline.
3)Cut out the smaller circles.
4)Apply quick setting contact adhesives between the outline of the piezo discs and the edges of the holes.
5)Paste the discs over the holes ensuring that they fit the contact adhesive outline.
6)Solder all piezo elements together in parallel.(Note Don't solder them in series because you'll need more current than voltage and those piezoelectric discs will cancel each other's power output when not actuated at the same time.)
7)Build a bridge diode which should look like this :
8)This is the diagram of how the circuit should be connected :
As a side note when we were wiring the piezoelectric discs to the power bank, we researched on the types of wires that should be joined to the power bank as the power bank only had a USB hole for input of current. So we had to cut one end of a USB cable in order to connect the piezoelectric disc to the power bank and we found the following picture cited from :(Brownlee, J. (2012, July 10). The Future Of Apple’s Dock Connector. Retrieved September 23, 2014, from www.cultofmac.com/178093/the-future-of-apples-dock-connector-feature/)
The picture shows that only the red and the black wires transfer current and the other two types which are white and green wires only transfer data. Therefore we decided to only use the black and the red wires to be connected to the bridge diode.
9)Glue foam pushers on top of the piezo discs.
10)Place the sole back into the shoe.
11)Walk around using the shoes for a day to see how much of the phone can be charged using it.
12)Keep checking the indicator on the charger every hour to see the amount that was charged.
13)Determine the amount of time spent walking needed to charge the power bank.
14)From the results we can decide if more piezo discs are needed for the shoe, and would adjust accordingly if this project is completed early.
- Risk and Safety: Identify any potential risks and safety precautions to be taken.
1. As this experiment involves drilling, take caution when using the drill so that the drill is always facing away from the body.
2. As the experiment involves soldering, take caution so that the user will not get burnt.