I am interested in analyzing surfaces of objects
to detect natural and man-made shaping of the object surface,
and I have been experimenting,
using a MP3 player/recorder to record the sound,
as I drag various fabrics attached to the player across the objects.

Fingerprint scanners operated about 500 DPI,
and the "ridges" that I want to "transducer"
are a little coarser than that.

I have experimented with various "transducer interface materials"
glued onto the MP3 player, and I have not found a
suitable material, as all materials have many
resonances, and those, combined with the
resonances of the MP3 players I have used,
tend to obscure the data associated with the surfaces,
that I want to analyze.

I would appreciate any input and ideas about
producing an audio signal that models a surface,
in a small portable, inexpensive package.

A small, low-power, laser probe would probably do a better job,
and I am hopeful of using an MP3 player/recorder for this,
as the cost, size, power consumption and frequency response
seems to be ideal.

Does anyone have any input on how
an optical mouse might work as a surface scanner,
and how it can be interfaced to an MP3 player?

The data from the MP3 player would be downloaded into
a PC and analyzed. I have experimented with a number of
time series analyzer programs such as SigView,
and would also appreciate any suggestions on how to best present the data,
so it could be interpreted by a layman.

Thanks in advance for any help you can provide.

--
Tom Potter
http://home.earthlink.net/~tdp
http://photos.yahoo.com/tdp1001