So, as far as I understand, speakers are basically coils coupled with permanent magnets, then when a current is run through the coil it creates a magnetic field, pushing out against the permanent magnet, moving the diaphragm that's attached to the permanent magnet and creating sound waves.
What I'm interested in is using a coil to do something similar but instead create human perceivable pressure. For example, something to lightly but noticeably push against your finger at a constant rate (not something that constantly moves back and forth like a speaker diaphragm).
If I just make a small coil out of some magnet wire and hook it up to a battery, I think that the magnetic field created by the wire would create a constant pressure against the magnet with the current being proportional to displacement. Is this correct?
If that's right then my real question is if this is possible to do without using a permanent magnet? I know you can create an attractive force to metal with a coil but is there a way to create a repulsive force?