Dear Dr. Will:

We probably need a definition of "MEMS structure" to confine the selection pool
in the first place. If you meant IC-process based MEMS, I would say Kris
Pister's micro Campanile of UC Berkeley. It is about 1000 um. If you include
others, there should be many made by Japanese that are taller. The pitfall is,
of course: Bigger structure tends to be taller, too! Perhaps slenderness is
more important, since it shows how tall a structure is in "its own world of
scale".

Another point, based on your interest of sensing away from surface, is the
length of microstucture protruding from the edge of substrate. For that
catagory, Michigan's nerve probes, Stanford's piezo AFM, and the microgripper
of myself (Berkeley) come in to my mind. Again, bigger structures are longer.

CJ Kim
Assistant Professor
Mechancial, Aerospace, and Nuclear Engineering
University of California, Los Angeles