A high resolution large-area array capable of resolving the three independe
nt components of a 2-D triaxial contact stress profile has been developed.
The array, composed of 4096 (64 x 64) individual stress sensing elements, w
as constructed with a fully CMOS-compatible fabrication process, allowing i
ntegration of the sensing structures with digital control circuitry. The in
dividual array elements have been shown to demonstrate linear responses to
both applied normal stress (1.59 mV/kPa, 0-35 kPa) and applied shear stress
(0.32 mV/kPa, 0-60 kPa). A spatial resolution comparable to the spacing of
the papillary ridges of the human dermis (approximate to 300 mum) has been
achieved within the 1.92 x 1.92 cm active sensing area of the array. Descr
iptions of the sensor structure, the required signal conditioning, and the
array architecture are presented in this paper. The results of electrical a
nd mechanical characterization studies are also outlined.