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I'm not sure if this belongs in Engineering, but if it does, please migrate the question.

What methods are used to vibrate objects extremely quickly? What are the most common?

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  • $\begingroup$ Not a task I've had to undertake, but I'd start with google.com/search?q=piezo+transducer $\endgroup$ – dmckee --- ex-moderator kitten May 6 '15 at 1:54
  • $\begingroup$ Extremely quickly is not precise. Do you have a particular frequency (range) in mind? $\endgroup$ – Alfred Centauri May 6 '15 at 2:57
  • $\begingroup$ @AlfredCentauri 200+Hz $\endgroup$ – Jimmy360 May 6 '15 at 2:59
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    $\begingroup$ Have you considered, for example, a loudspeaker and audio amplifier? $\endgroup$ – Alfred Centauri May 6 '15 at 3:13
  • $\begingroup$ A couple of hundred hertz is extreme?!? I thought you had a hard problem. The loudspeaker suggestion is robust, and easy. $\endgroup$ – dmckee --- ex-moderator kitten May 6 '15 at 4:50
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Very often, in the audio range people will use speaker coils. Audio speakers are designed to give displacements on the order of a few mm over a range of 20 Hz to 20 kHz - with lower amplitudes at the higher frequencies. Since they are mass produced, they are quite cheap and robust. Take off the membrane, and you have an instant vibrator. Just add AC current... You want to pick a coil that is suited to the frequency range you have in mind - woofers for the lower frequencies, tweeters for the high end, and mid-range speakers - well, for the frequencies in between.

An example of one of the most beautiful experiments I know that used this method (many years ago) was the classical experiment described in Squires' book on "Practical physics" (I have quoted this one before...). There, the coil was used as part of the suspension mechanism for a reflector that had to be isolated from vibrations. In essence, they created a mechanism that allowed a short spring (1 m length) to behave like a long spring (1 km length), thus damping most vibrations. I reproduce here a diagram that shows the voice coil being used:

enter image description here

I am not associated with the publisher or author of the book - although I was lucky enough to be taught by him as an undergraduate, many many years ago. So I have heard him talk about this experiment first hand...

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