Can an electromagnetic field be created in a non-metallic coil?
Yes, you can make a solenoid without a metal wire. The best conductors aren't metal at all, they're ceramics (i.e. superconductors). Water with impurities will work fine as a solenoid. 

If you decide to use an actuator, you'll obviously have to have that have some kind of ferromagnetism or conductivity in the actuator to be capable of induced currents, but this still doesn't require any sort of metal or magnetism on the solenoid coil.