Re:Time Is Different
by direwolf20 on Friday February 27, 2026 @06:14AM
(#47179173)
Some types of motors don't require permanent magnets. If we need more motors than we can make permanent magnets, we'll adapt, perhaps with an efficiency loss.
Motors with permanent magnets are preferred because they are much more cost- and energy-efficient, even with the painful reliance on REEs. There is a very strong incentive to find alternatives but nothing comparable has been found yet.
There are of course non-eletric alternatives like hyrdaulic and pneumatic actuators but they are mostly good for power, not dexterity. The size and complicated fluid dynamics simply are not conducive for fine motor control. I do think these will play a large part eventually because even electric motors cannot economically produce enough force to be practically useful. Like, last I checked, the base-level Unitree robots can lift 2kg or so? Not even enough to lift a load of laundry.
At this point I suspect we'll end up with hydraulics for strength (arms, legs, torso) and electrics for dexterity (grippers)
On the other hand, the constraints on robotics are largely supply chain-related. The current SOTA for dexterity in robots requires motors, which require powerful magnets, which require Rare Earth Elements, which are critically supply-constrained.
To be precise, the elements are actually abundant in the Earth's crust, just that extracting them is very expensive and extremely toxic to the environment, and so far only China has been willing to sacrifice its environment (and certain citizens' health), which is why it has cornered the market. Scaling that up to the required demand is a humongous logistical, political and regulatory hurdle (which, BTW, is why I suspect the current US adminstration is busy gutting environmental regulations.)
Now there may be a research prototype somewhere in some lab that is the "Attention Is All You Need" equivalent of actuators, but I'm personally not aware of anything with that kinda potential.