Permanent magnet electric motors pretty much consist of three primary materials: copper, steel, and the magnets, the latter made of rare earth elements. The Spark e-motor is no different. It's how they are arranged that would seem to set this motor apart, as well as the processes used to assemble each that are designed to minimize waste.
For example, the copper coils are fabricated using square wire that is cut, trimmed and bent by robots into the "hair pin" shapes required to create the windings. Savagian explained that using square wire is a more efficient use of space. While it takes an experienced technician 15-minutes to manually insert each of the 120+ copper 'hair pins' into their insulating wrappers in the motor, after that robots continue the assembly process, from seating the pins in the stator to welding the free ends into a continuous coil, to dripping the insulating vanish and epoxy onto the newly welded ends. This last step of dripping, instead of dipping, the exposed ends of the coil into their respective coating baths cuts production time and waste.
The magic of the Spark motor, however, starts to become obvious once you see how the rotor is assembled. This is where the tiny, Chiclet-sized rare earth magnets are mounted. There are two sizes of them and they are positioned at various angles to the radius of the rotor. But what's intriguing isn't so much the magnet themselves, but the how they are spaced and the tiny 'eyebrows' and pinholes that are part of the rotor assembly. These aren't there as an after-thought or by-product of a sloppy manufacturing process. They have a very precise purpose, as Peter Savagian illustrated using my luncheon paper napkin.
The Spark motor is a three-phase motor, meaning it has three overlapping sin waves in its power flow, the purpose being to smooth out the operation of the motor as it spins. But within in these sin waves are small peaks and troughs. The purpose of the air gaps in the form of the 'eyebrows' around the slots into which the magnets are epoxied, and the even smaller pin holes closer to the outside of the rotor are to reduce these peaks and valleys, directing the magnetic flux fields in such a way as to further quiet the motor and smooth out its operation.