For this project we were tasked with converting one form of energy into another. The most common form of energy to begin with was chemical energy. Our group brainstormed various kinds of energy that we could convert chemical (or other types of) energy into, such as sound, light, electrical, and so on. At first we wanted to convert chemical energy into sound to make a speaker for a phone, but it proved too difficult. We considered converting electrical energy into electromagnetic energy by making a microwave, but quickly realized this was too far-fetched. Finally we settled on converting chemical energy into electrical energy by making a battery. Initially we tried making a penny battery which uses pennies, cardboard, and tin foil. The cardboard is soaked in vinegar or salt water and then its all taped together in a certain pattern with leads of LEDs on both ends. This proved difficult, as you have to be very careful that the cardboard doesn't touch and they are all aligned perfectly. After failing to get hardly any voltage when tested with a volt meter, we decided to try making a lemon battery.
We were hoping that our lemon battery would produce enough voltage to power a cell phone when we started this project. We thought that a lemon battery would be a good choice since we had an unlimited supply from my lemon tree at home. Initially we used whole lemons and stuck copper wire and zinc plated nails into the lemons, which then connected to a USB. Having two types of metal suspended in the acidic lemon should create a battery. This did not work with the USB, so we decided to try to power a LED light instead. We experimented with the number of lemons, and then discovered that if we cut the lemons in half, we were able to get more voltage. Our next discovery was that rolling the copper wire gave us a higher density of copper which increased the voltage as well. The zinc lost electrons more quickly than the copper, making it the negative electrode, while the copper was the positive electrode. The electrical current was created because the two metals have different tendencies to lose the negatively charged electrons. I learned, after the fact, that the more acidic a fruit is, the more energy it generates, so lemons were a very good choice!
Slideshow
Below is the slideshow that I created which shows the various steps of our project:
Proof of Efficacy
Below is the proof of efficacy document that I created for this project:
Reflection
Overall I think this was a successful and interesting project. I didn't really understand much about converting energy and how batteries worked before this. I liked working with this group to figure these challenges out. I think one of the peaks was that we are all good friends, so we were able to communicate well and did not argue over choices. Another peak was that because we all found this project interesting, we all seemed to be engaged and willing to share the work load.
While this project was successful, it wasn't without its challenges. One of the pits was that our group felt unsure about the chemistry behind the project which made us nervous going into it. Because of that, we floundered a little bit in the beginning until we had some help from Mrs. Vogel. Another pit was that we felt pressed for time. Since we changed our project multiple times, we didn't have as much time as we would have liked for the final project we decided on.