SparkFun Forums

[Myself]

Once in a while, it would be nice to have motion without magnetic fields. Anything with a compass, for instance. Maybe you also want to drive a little needle, or unlatch a door, or.... whatever.

Camera lenses have had ultrasonic motors in 'em for years. I believe it's a ring of piezoelectric material, but haven't looked into it in much detail.

Newscale makes some totally wild little motors that use a piezoelectric twisting effect to "hula-hoop" a shaft around.

Are there other offerings in this space? How would a hobbyist get their hands on them? I feel like SFE could help here...

[lyndon]

Muscle wires?
https://www.sparkfun.com/products/11900

[jremington]

Hydrostatic/pneumatic motors and cylinders come in all imaginable sizes and won't be going away, ever!

[Valen]

Muscle wires?
https://www.sparkfun.com/products/11900

Since a fair amount of current runs through such a wire, there is still a magnetic field emanating from it. Weak perhaps, but still there. If that is a problem is up for experimentation.

[lyndon]

Good point. I was going to suggest pneumatics or hydraulics, but you'd potentially have fields from the coils of the solenoid valves.