17-year-old designs rare-earth-free motor that could transform electric car industry

Robert Sansone could pave the way for the sustainable manufacture of electric vehicles that do not require rare-earth magnets.

Robert Sansone has already developed 60 engineering projects in his spare time. And he’s only 17.

A few years ago, Sansone saw a video about the pros and cons of electric cars. The video explained that most electric car motors require magnets made from rare earth elements, the extraction of which can be costly, both economically and environmentally. The rare earth materials needed can cost hundreds of dollars per kg. In comparison, copper is worth $7.83 per kg.

The high school student had heard of a type of electric motor, the synchronous reluctance motor, which does not use these rare earth materials. This type of motor is currently used for pumps and fans, but is not powerful enough on its own to be used in an electric vehicle. So Sansone started thinking about ways to improve his performance.

Within a year, Sansone created a prototype of a new synchronous reluctance motor with greater rotational force or torque and efficiency than the existing ones. The prototype was made from 3D printed plastic, copper wires and a steel rotor, and was tested using various meters to measure power and a laser tachometer to determine speed rotation of the motor. Her work won her first prize and $75,000 at this year’s Regeneron International Science and Engineering Fair (ISEF), the largest international STEM competition for high schools.

Less durable permanent magnet motors use materials such as neodymium, samarium and dysprosium, which are in high demand as they are used in many different products, such as headphones and hearing aids.

Synchronous reluctance motors do not use magnets.. Instead, an air-gap steel rotor lines up with the rotating magnetic field. The reluctance, or magnetism of a material, is the key to this process.

Instead of using inner tubes, Sansone thought he could add another magnetic field to the motor. This would increase that salience ratio and in turn produce more torque. His design has other components, but he can’t reveal more details as he hopes to patent the technology in the future.

Materials for synchronous reluctance motors are cheap, but the machines are complex and notoriously difficult to manufacture. The high manufacturing costs are therefore an obstacle to its generalization, and a major limiting factor to Sansone’s invention.

Sansone hopes that with new technologies like additive manufacturing, like 3D printing, it will be easier to build in the future.

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Image: www.smithsonianmag.com

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