A CMOS Compatible Traction Stress Sensing Element For Use In High Resolution Tactile Imaging

A microstructure capable of resolving the three independent components of a point traction stress has been developed. The sensor exhibits an independent, linear response to each of the three components of an applied traction stress with measurement sensitivities of 130 mV/(V*kPa) in the normal stress mode and 26 mV/(V*kPa) in the two shear stress modes. The sensor was realized using a fabrication process which is fully CMOS compatible to allow for the future integration of local processing and control circuitry. High spatial resolution robotic tactile sensing may be possible with the sensor structure as each element is less than 300 x 300 /spl mu/m in size. A description of the sensor structure and the required signal processing follows, with mechanical characterization data included.