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Effectiveness of sugar as a piezoelectric material Answered

Most of the sites discussing piezoelectricity mention that sugar crystals can be used, but I have not found any examples of them being used. I've just tried it with about a 1cm chunk of low quality (conglomerate of small ~3mm crystals) crystal, and got a good 100mV wave when tapped with a pencil. I've not tried applying a signal to it yet, and some better single crystals are growing at the moment, so I was wondering how well it works compared to commercial piezoelectric compounds.

I've not done anything like this before, so if anyone knows where I can find information of the best way to mount and apply a signal to the crystal, it would be appreciated.

Thanks in advance.


Can you point us to these sites discussing piezoelectricity mention that sugar crystals can be used?
The charge develops through deformation of the crystal - but it obviously can't deform irreversibly.
Quartz is tough because there's a large degree of covalency in the lattice, sugar is mostly held together by hydrogen-bonds which are much weaker.


Hmm, it may be of academic value only.
I've E-mailed my old colleague Ben Davis, let's see what he knows.


I would guess that sugar's fragility and hydrophilia stop most people using it.

The individual crystals seem reasonably strong, but I would have to agree that the susceptablity to water damage prevents commercial use. I have thought about giving it a thin layer of wax to seal it, but I guess that it would absorb too much of the energy and make the whole thing ineffective.

That sounds like a better idea, although I don't know whether the sugar will like the solvent in it though. Alternatively, sealing one side of the container with a thin rubber membrane may work better than coating the crystal.

You can test the spray on an ordinary sugar cube.