Craig Niederberger wrote:

> I'm working on a PIC application to compute average and peak pressures
> in
> a biomedical application, and can't seem to locate sensors--I was
> wondering if anyone could help me out.  The sensors themselves need to
> be
> relatively flat--they will measure pressure between human skin and an
> object, and thus can't protrude too much lest they do damage to the
> human
> whose skin is being measured.  I've calculated that the pressures to
> be
> measured will be in the range of 0-20 psi.  I've looked high and low
> on
> the web for the last couple of days to no avail.  Can anyone help?
>
The kind of transducer you're looking for is more along the lines of a
compression load cell. Made by hundreds of companies such as: Transducer
Techniques, Sensotec, PCB Piezotronics, Eaton LeBow, Entran, Honeywell
Microswitch, Interface, etc. Some of these companies have web pages. I
don't have the addresses handy at the moment.

There are also thin film matrix type force sensors made by companies
such as Force Imaging Technology, Tekscan, and Cooper Instrument
Systems. Basically, these sensors consist of a compressible resistance
compound between two laminated thin sheets of plastic film with
conductive ink like printed circuit traces. Overall, they're much less
that 0.010" thick. Tekscan, I know, does biomedical applications with
sensor arrays for both hands and feet, as well as custom arrays. Brace
yourself, though. They're out to sell you a system which runs about $20k
to $30k (plus sensor arrays). Force Imaging Technology used to have a
small demo kit available for a few hundred dollars.

Hope this is of some help. Maybe this will jar someone else's memory out
there and they know of a cheaper source.

-Frank


Frank Richterkessing

FRANK.RICHTERKESSING@APPL.GE.COM