Motor selection for your EV car/drone design, material economics matters

Over the decades of scientific research, the miniaturization and increase in the power efficiencies of electronics devices is an important area achieved by the electronic industry. Advanced semiconductor technology could pack billions of transistors in a thumbnail sized today's chips compared to a thumbnail size transistor in late 50s. Tiny BAW and SAW filters replace bulky traditional LC filters. The bulky powerline Transformers used to step down AC voltage to lower level for converting it into DC power for electronics systems are now made quite small due to switching power supply design. And even in the batteries-area, there is some amount of miniaturisation happening. The most widely used electrical machine 'electrical motor' is also miniaturised and made power efficient, and also light in weight, so that it can be even used in solar powered aeroplanes and drones as propellers. All these achievements is done through innovation in material-science research and the processing of those materiperals. In some cases such as Silicon in ICs, the material used is abundant and nothing much to worry. But in many other cases the material is short in supply and has a lot of economical impact, if the device made using a less-abundant material is produced in very large volumes. Some of the important materials which are short in supply and expected to be used in larger scale ...