Electric motors come in many size and types, but the homopolar motor is without a doubt the simplest motor in the world. While the efficiency and torque is lower compared to ordinary motors, the ease of construction and small size makes it a very interesting build and a possible perfect fit for small-scale mechanics. All you need is a battery, neodymium magnet and copper wire, that’s it! In this video from Nicole Zavi a normal double A battery is used, but there is not reason why a button cell can’t be used instead and result in a motor that only measure a couple of millimeters in width and height. This video is the best we have found so far, since it not only shows many variations of wire design and how to use it for a practical purpose, but also the importance of adjusting the tightness of the wire and balancing it on the battery. To make it easier to balance it, we recommend making a small dimple on the top of the battery with any metal tool, like a screwdriver. We believe that this type of motor has more potential then it has gotten credit for in the past, and we would love to see how you use this in your project, so be sure to send us your homopolar pictures or videos!