Some time ago I posted a post to ask for information on small force sensors
to measure the Groung Reaction Force for mice(body weight around 25 grams).
Here are the responses I have got. As some folks asked for them.
I have seen a different approach taken by Robert Full at UC-Berkeley. He
uses a semi-hard, transparent gel and was able to correlate diffraction
patterns with force in insects.

He is very approachable and would likely provide you information on the

Interface makes some ultra low capacity load cells (ULC series) in that
range - - that only
need a thin aluminum plate to
put the on. Probably ~ $400... Pressure Profile Systems may have a flat
pressure pad in that range too but it will be expensive.
i'm not sure if there's any way to design a circuit to make these
things work in the range you're describing ... but tekscan
( ) makes inexpensive flexible force
sensing resistors
that are labelled for 0 to 1 pound range. i know you can modify the
drive circuit to increase the range, so i wonder if you can do the
same to decrease the range.

as far as size, they're a bit large (0.375 inch diameter) ... but
again, i know they can make them to custom shapes/sizes ... i just
don't know what the lower limit for size is, or what quantities you
need to order to get custom sizes.
Dear Mr. Liang,

You can consider Kistler piezoelectricforce sensor. Please visit for more information.

If you are located in China, please let me know your phone no., so I can
talk to you on the phone.

Best regards,

Jacky Ma
Regional Manager
Kistler China Limited
Unit D, 24/F, Seabright Plaza
9-23 Shell Street, North Point, Hong Kong
Tel + 852 2591 5930
Mobile + 852 9651 1747
Fax + 852 2591 1885
I know a french research professor, Patrick Even, working in Paris, at the
INAPG institute, who developped small metabolism cage for mice, that also
can record mice activity with piezoelectric sensors positionned under the
bottom of the cage. He also created a start-up to sell these original cagesYou can contact him at this email adress :
Issues to think about:

Is the sensor stiff enough? If the natural frequency of the sensor is low,
then you will end up with a lot of low-frequency noise that will screw up
your signal. Simply for measuring maximum forces this might not be a huge
deal, but to measure details about the force patterns this might be a big
concern. I would shoot for a natural frequency >500 Hz.

The following paper might also be useful: