US Patent 7434445 - Power spectrum analysis of microcantilevers

http://www.freepatentsonline.com/7434445.html

Microfabricated cantilevers are an important component of Atomic Force Microscopes as well as many MEMS sensors. This patent from Asylum Research teaches an apparatus for providing a more sensitive calibration of the cantilever using a power spectrum detector to detect shifts in resonance frequency. Claim 1 reads:

1. An apparatus for determining cantilever parameters, comprising:

means for measuring a drag force acting on a cantilever by monitoring a deflection of the cantilever;

means for determining a power spectrum of the cantilever;

means for measuring motion of a base of the cantilever; and

means for determining one or more characteristics of the cantilever based on the motion of the base, the power spectrum, and the cantilever deflection.