If you buy a Tesla or other electric vehicle, you expect the motor(s) to, perhaps, get you to work and back home, where you dutifully plug it in for the next day’s commute. Imagine, however, having an electric motor that doesn’t just last through the day, but could theoretically run for thousands — many thousands — of years on a single AA cell. YouTuber lasersaber has created just such a device, and while it won’t come close to powering your car, it’s still very interesting.
As you might suspect, the key to this motor’s efficiency is that it works with extremely low friction. This is enabled here by the magnetic levitation of a rotor made with pyrolitic graphite. Four permanent magnets attached the top of the rotor are moved around by electromagnets that provide power, forming a sort of very low power, high efficiency stepper motor. A number of resistors, a capacitor, and a reed switch are used to control the unit.
A large portion of the video below is spent explaining just how impressive the device’s power consumption is, and at a low RPM setting it uses only .15 microamps at 33millivolts, for a grand total power consumption of less than .005 microwatts. This means that theoretically, the device could operate for 89,880 years on single AA battery. It’s an amazing feat of efficiency, and as ‘saber notes, this could possibly be made even more impressive if the device was constructed inside a vacuum chamber!