Can an electromagnetic field be created in a non-metallic coil?

Question

OK, so here's a simple one. When current flows through a wire, it produces a tiny magnetic field. If you bend the wire into a spiral, the fields of each loop merge together forming a field you can actually measure.

But does the conductor have to be metal, or would any conductive material work? E.g., would a plastic tube full of water still produce the same magnetic field? [Assuming the water has enough impurities to be considered a "conductor" to start with, which it usually does.]

Edit for Clarification: OP is talking about a simple electromagnetic coil, without regard to core material or application. Assuming Air Core, would a coil of water in pvc tubing, electrified, produce a measurable magnetic field?

Answer 1

Since the flow of charge through anything constitutes current, and since current creates a magnetic field, the short answer to your question: "Can an electromagnetic field be created in a non-metallic coil?" is "Yes".

Answer 2

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.

Answer 3

For the sake of ambiguity:

If by solenoid the intent is just a coil & such a coil is to carry current & thus generate a magnetic field.

Yes. Water can easily conduct electricity & with this electrical current flowing around the coil will produce an magnetic field. How good compared to a coil made out of wire? not that good Why? the radius of the coil. The radius influences the inductance and the length & turns influences magnetic strength

B=μI*n/l

L=μr²n²π/l

Could you make the insulation of a waterpipe the same as the enamel insulation on a metallic conductor?

If it is todo with a solenoid associated with linear movement:

Any conductor will do. The key here is the permeability of the material.

http://en.wikipedia.org/wiki/Permeability_%28electromagnetism%29#Values_for_some_common_materials

Compare Iron ( 2.5×10−1 ) to water ( 1.256627×10−6 ) and more importantly to Air (1.25663753×10−6) as it would be an air-cored Solenoid

That is a factor of 20,000

Answer 4

For a simple solenoid, yes, it has to me metal. Further, it has to be a ferrous metal.

A solenoid works by simple magnetism. Energise a coil to attract a ferrous material.

There are other systems though, called Linear Motors which at first glance look like a solenoid, but in fact work on a completely different principle. These use a powerful magnetic field to induce a current into a conductive non-ferrous material (commonly aluminium) which then in turn generates its own opposing magnetic field. These two fields repel each other and the non-ferrous material moves. It's how "Maglev" trains work.

Answer 5

Yes it would, but depending on the medium you'd run into some serious implementation obstacles. In case of water:

• Once a DC current flows through water, it begins to split into hydrogen and oxygen.
• You somehow have to prevent evaporation