First a Physics lesson (sorry):
When some materials (quartz and many others) have an electric charge placed across them, they change shape a little bit. It works the other way around -- that's how gas lighters work. This is called the Piezo effect.

The movement is not very much, but it is possible to amplify it, because the force is quite large. See the link for an example of 1 inch movement.

I was originally thinking of applying a spark to standard piezo material, to get it to quickly jump. The jump would then used to flick some small wings down. The wings would hopefully move further than the piezo device because of the high speed.

The advantage of a spark is that it is fast, and might even be applied from external sources. That means the power source would not necessarily be on the fly.

But I came across the Piezo fan, and wondered if that could be developed to give enough lift.
-- Ling, May 31 2005

Piezo fan http://www.piezo.com/sfrfn.html
[Ling, May 31 2005]

<wonders if seismic or tectonic pressure ever causes piezo effects above ground.>
-- bristolz, May 31 2005


What's the spark for?
-- ldischler, May 31 2005


The spark is to supply power, quickly and at high potential, to get the best response from the Piezo device.

Bristolz: Thunderstorms? You might be on to something.
-- Ling, May 31 2005


A spark won't provide an electric charge across your crystal. Sparks are how nature gets RID of charge.
-- ldischler, May 31 2005


I think a spark would work, if you had (for instance) one side of the xtal grounded and the other side contacting a metal plate with a sharp point on it. Spark jumps from source to point, thereby delivering volts to one side of the crystal, no?
I don't know if this could be used to provide remote power to the fly. But if I remember some physics, you can use one spark- gap to pick up the RF dissipated by another spark gap (ie, basically radio).
-- Basepair, May 31 2005


Now if only the teachers would formally apolgize to students at the start of each lesson, the world would be a better place.
-- zeno, Jun 01 2005



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