How to Build the World’s First Motor: The Faraday Motor
I’m Ken Kuwako, your Science Trainer. Every day is an experiment!
Have You Ever Seen a Motor Like This!?
First, take a look at this video. I guarantee it’ll surprise you! For some mysterious reason, a piece of aluminum foil is spinning like crazy right on top of a battery.
At first glance, it looks like nothing more than some foil, a battery, and a thumbtack. Yet, the foil keeps spinning and spinning. When I first saw this, I remember thinking, “How is that even moving?” If you’re scratching your head right now, you’re not alone!
Actually, this “magic” device is a type of motor that converts electrical energy into motion. Specifically, it’s a modern DIY version of the Faraday Motor, the very first motor ever invented in history. Today, I’ll show you how to build this surprisingly simple motor and explain the scientific principles hidden behind the fun.
The best part? You can find all the materials at a 100-yen shop (or any discount store). No advanced degrees required! By the end of this post, you’ll understand the “secret” behind this trick. Ready to open the door to the world of science?
The Science Recipe
Materials
Aluminum foil, a battery, a thumbtack, and 5 ferrite magnets.
Believe it or not, you can grab everything at your local dollar store!
Instructions
① Create the Base
Stack five or more ferrite magnets and wrap them neatly in aluminum foil.
② Create the Rotor
Cut a strip of foil about 5cm wide and fold it in half lengthwise to create a 2.5cm wide strip. Then, fold that strip in the middle.
Now, shape this strip into something that looks like a chestnut or a little “Slime” character.
③ Set the Stage
Place the battery on top of the base you made in Step 1, then balance the thumbtack on top of the battery.
④ Gently Balance the Foil
Carefully place your “chestnut-shaped” foil on top. Adjust the length so that the two ends of the foil just barely graze the foil-wrapped magnets at the bottom. Watch the video closely to see the exact positioning.
This part is the key!
Once you let go, the foil will start spinning on its own.
Why Does It Spin? The Science of the Faraday Motor
The secret lies in the relationship between electricity and magnetism. Remember: when an electric current flows through a wire inside a magnetic field, it experiences a force called “Electromagnetic Force.” The Faraday Motor uses this very force to create rotation.
Breaking Down the Mechanism
- Current: Electricity flows from the positive terminal of the battery, through the foil, and down toward the magnets.
- Magnetic Field: The magnets at the base create a strong magnetic field (an area of magnetic influence) around the battery.
- Force (Electromagnetic Force): The interaction between this current and the magnetic field creates a “pushing” force on the foil.
We can explain the direction of this spinning force using “Fleming’s Left-Hand Rule.” If you point your middle finger in the direction of the current and your index finger in the direction of the magnetic field, your thumb points to the direction of the force. Because the current flows and the magnetic field is constant, the foil receives a continuous “nudge” in one direction, causing it to spin indefinitely.
This invention by Michael Faraday is the “great-grandfather” of the high-performance motors we use today. Everything from vacuum cleaners and fans to electric trains operates on this same fundamental principle.
This experiment lets you feel the dynamic power of electricity and magnetism without any specialized tools. Give it a try at home and experience that “Aha!” moment for yourself!
You can also make a Faraday Motor using a different design. Check this one out:
This version uses a bent copper wire. It actually tends to be a bit more stable and can spin even faster!
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