The google keyword you are looking for is "Vickers hardness" which is
mechanical engineering speak for how much "compliance" you get when you
poke a sample of interest with a pointed stick. (After you specify the
pointiness (tip dimensions), the sample has a flat surface, and you know
the hardness of the tip of your stick.) Obviously, the stick must be
harder than the crystal, but in this case you can't loose because it
looks like lysozyme crystals have the lowest Vickers hardness ever measured:
http://dx.doi.org/10.1016/S0022-0248(98)01096-3
http://dx.doi.org/10.1080/14786430410001716791
As with many things in engineering, there is more than one way to
measure the "stiffness" of a substance. Perhaps a more elegant method
would be Brillouin scattering. By "elegant", of course, I mean more
accurate and harder to understand, but it looks like this was done as well:
http://dx.doi.org/10.1016/S0022-0248(01)01092-2
This is about as far as I got looking into this at one point. Let me
know if you learn anything more!
-James Holton
MAD Scientist
Frank von Delft wrote:
Hi,
I don't remember ever seeing any references to this, and am also not
quite sure where to start looking -- but the BB readership tends to
dredge up this sort of thing:
Has anybody published (or just done) estimates of the magnitude of the
forces that hold a crystal together? E.g. how hard would I need to
poke it with a pointed stick to make a hole in it? (Or conversely,
how pointed would the stick need to be.)
(I thought Alex McPherson's AFM papers might point me there, but they
only say what nominal forces they used, not what forces demolished the
crystals.)
Cheers
phx
