I have thought about this some also. I think you should be able to accomplish
this by using an AFM in its pull-off force mode. For instance, the Topometrix
AFM we have here allows me to raise and lower the tip (by as much as 12 microns
for our long-range scanners) while looking at the deflection of the tip. The
key would be matching the cantilever stiffness of the AFM tip to that of the
beams you are measuring such that you are able to see when the tip touches the
beam and when the beam contacts the substrate. Of course, you will also have to
center the tip over the beam, which could be a problem depending on the sixe of
the beams.

Michael Houston
email:[email protected]