# Vibrate a string with electricity? Best ways?

1. Sep 23, 2015

### MauriceWaves

Is it possible to vibrate a string with electricity? I'm guessing an electro-magnet placed close to the string would be able to vibrate it.

If the electro-magnet is used to vibrate the string, I'm guessing the electro-magnet should be pulsed at the fundamental resonate frequency of the string? Maybe different frequencies or harmonic intervals are more efficient? And I wonder should the electro-magnet be fed a sine-wave or is some other wave more appropriate to excite the string?

Also is there anything that would tell me where the most efficient placement of the electro-magnet would be?

2. Sep 23, 2015

### UncertaintyAjay

As far as I know, an electromagnet will do nothing to string. Absolutely nothing, unless you physically hit the string with the electromagnet.

3. Sep 23, 2015

### MauriceWaves

Here's a project where electro-magnets are used to actuate strings on a piano.

http://music.ece.drexel.edu/research/mrp/actuation

Unfortunately I haven't been able to find much else on the internets.

4. Sep 23, 2015

### UncertaintyAjay

Ohhhh, you're talking about metallic strings, I was thinking of the rope thingies. In that case yeah. But you have to vary the field of the electromagnet. Doesn't have to be resonant frequency though. As long as you have a changing magnetic field, you'll move the wire. So, if your current to the electromagnet oscillates( like a.c , which is sinusoidal, but it doesn't have to be), the string will vibrate

5. Sep 23, 2015

### billy_joule

An EBow is one such device:

https://en.wikipedia.org/wiki/EBow

I used one a few years ago, great fun.