US Patent 7971489 - CNT load cell

http://www.freepatentsonline.com/7971489.html

This patent from Applied Materials teaches a strain gauge formed using carbon nanotubes used in characterizing semiconductor wafers in environments having background EM noise. Claim 10 reads:

10. A test wafer assembly for characterizing semiconductor processing equipment, comprising:

a first wafer;

a second wafer, parallel to said first wafer;

a plurality of spaced-apart carbon nanotube load cells positioned between and attached to both of said first and second wafers; and

an electrical device, independently electrically connected to each of said plurality of carbon nanotube load cells;

wherein said electrical device is configured to monitor and record the resistivity of said load cells.