Device for detecting interaction with an object

U.S. Patent # 7849738 (2010)
Inventors: B.J. Larson and J.W. Baier.

A device and method for the detection of the interaction between two or more objects is disclosed. The device utilizes electrical impedance spectra measured from a piezoelectric element attached to one such object. Comparison of such spectra along a range of traverse allows precise estimates of distance to be made. One useful application is the topographical mapping of a surface.