The new parts thread has a lot of great suggestions for electrical parts that could be recreated in spintronics. My favorite thing about spintronics though is all of the things that are much easier to do in spintronics than in electric circuits. So I wanted to turn the idea on its head and create a megathread for compiling interesting mechanical devices that you all think could be interesting in a spintronics circuit. In turn, I, or anyone else who feels like it, will try to derive the governing equations for an analogous ideal electrical element.
As a general rule of thumb, I’ve found that devices that store energy as potential energy generally have (possibly nonlinear) spin capacitance, and devices that store energy as kinetic energy have spin inductance. Mass and momentum are the natural carriers of spin inductance, which makes sense because the units for spin Henrys reduce down to just kilograms. This also explains why spintronics circuits have orders of magnitude more parasitic inductance than electric circuits, which more often suffer from parasitic capacitance. However, I would love to be proven wrong with a device that demonstrates capacitance and stores energy as the kinetic variety.
So, please post any interesting mechanical devices you know of here.