# Thread: Do moving charged particles emit a magnetic field?

1. Example.

Electrolysis, you have sodium and clhoride ions moving, they have electric fields which are moving, does this mean they emit a magnetic field?

2.

3. Yes, uniformely moving charges produce magnetic fields, according to Maxwell's equations; accelerating charges produce electromagnetic radiation.

4. Cool Thanks.

So what do you think of using a tube with an electrolysis solution in it (fully saturated) and a coil around it to induce a current in it due to the?moving charged particles.

Also do you happen to know what the current of a human nerve impulse is?

5. So what do you think of using a tube with an electrolysis solution in it (fully saturated) and a coil around it to induce a current in it due to the?moving charged particles.
The problem is that just as moving charges generate magnetic fields, it is changing magnetic fields ( or movement through a field ) which generates current. A static magnetic field will not do anything in a coil.

Also do you happen to know what the current of a human nerve impulse is?
I'm afraid that is not my area of expertise. Perhaps someone else can answer this.

6. Originally Posted by ChaosD.Ace
So what do you think of using a tube with an electrolysis solution in it (fully saturated) and a coil around it to induce a current in it due to the?moving charged particles.
It is not quite clear what you are asking (too many "its"). Are you suggesting passing a current through the electrlyte and inducing a current in tje coil, or the other way round?

Also do you happen to know what the current of a human nerve impulse is?
This is complicated because nerve signals are not carried by a current flowing down the nerve like a wire. It is more like a chain reaction of ion-transport current across the membrane that ripples down the nerve.
Action potential - Wikipedia, the free encyclopedia
I assume the currents involved are pretty small (of the order of milliamps) because the voltages are just 10s of millivolts. But I don't really know.

7. Yes I am indeed asking can you use the moving charged particles in nerves to induce a current?

8. Originally Posted by ChaosD.Ace
Yes I am indeed asking can you use the moving charged particles in nerves to induce a current?
In principle. Whether this is actually doable in practice, I don't know. You may want to ask that in biology.

9. Originally Posted by ChaosD.Ace
Yes I am indeed asking can you use the moving charged particles in nerves to induce a current?
Not very easily. Human beings can be exposed to very high magnetic fields with no discernible effect since there is very little interaction between neuron polarization/depolarization and magnetic fields, which imply there is very little actual movement of charged particles (and/or purely symmetric motion of charged particles.)

10. Charged particles in motion is the definition of a current, isn't it?

11. Originally Posted by ChaosD.Ace
Yes I am indeed asking can you use the moving charged particles in nerves to induce a current?
As harold's question reveals, your query is a bit vague. It's not entirely clear if you are asking if moving charged particles constitute a current (answer: yes); whether such a current would generate a magnetic field (answer: yes); or whether one can set charged particles into motion under the influence of an external magnetic field (answer: yes, but the field must be time-varying when viewed in the frame of the charges). As an example of the latter, patients frequently report interesting effects if they move during an MRI scan. Vertigo is perhaps the most commonly reported effect. Recent studies suggest that at least some of those cases are the result of Lorentz forces acting on ions.

12. Yes I do understand what the definition of current is.

Strange understood what I meant, which is having a coil around the spine, when I said "Yes I am indeed asking can you use the moving charged particles (involved in action potentials) in nerves to induce a current (in the coil)?

So I am not trying to move the ions in the spine, rather I want to use their motion to induce a current somewhere else, since they will produce magnetic fields.

Sorry for the confusion.

13. Originally Posted by ChaosD.Ace
Strange understood what I meant, which is having a coil around the spine, when I said "Yes I am indeed asking can you use the moving charged particles (involved in action potentials) in nerves to induce a current (in the coil)?
I agree with Strange in that it is probably doable in principle, but my feeling is that the resulting current will be so small as to be practically negligible.

14. What about using a superconducting/nanotube coil etc. There must be some method of amplyfication right?

Anyhow the whole point of this is to detect exactly which nerve fibres are active, so the induced won't be driving anything power-hungry. This links in to my neuromuscular actuation question because this is supposed to be the principle behind a method of synchronising biological muscles to artificial muscle fibres, what do you think of it?

15. Originally Posted by ChaosD.Ace
What about using a superconducting/nanotube coil etc.
If you are using science fiction technology, then why not just nanoprobes which would detect the voltage directly?

16. I am not using science fiction.

17. Originally Posted by ChaosD.Ace
What about using a superconducting/nanotube coil etc.
I am not aware of any materials which are superconducting at body temperature; obviously including a cooling system with this wouldn't be practical or even doable.

Anyhow the whole point of this is to detect exactly which nerve fibres are active, so the induced won't be driving anything power-hungry. This links in to my neuromuscular actuation question because this is supposed to be the principle behind a method of synchronising biological muscles to artificial muscle fibres, what do you think of it
I can't really comment on this, it's not my area of expertise.

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19. Thanks, I just don't want to rely on brain wave readers.

20. Which is why I included the other links.

21. So thanks for the links, Electromyography has too many limitations:

Requires power, I can't afford to waste energy on the detection mechanism.
I need to be able to detect every muscle in the human body (even the tiny ones) (sometimes simultaenously) and need to intercept the impulses before they reach the muscle, I don't feel confortable having a hundred electrodes on the human body.
I prefer to have a centralised detector.

I supose I could use Brain Waves but that relies on patterns of motion rather than individual muscles, I'll make a design for a brain wave reader though.

Thanks for the help.