CMOS-compatible traction stress sensor 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 51 mV kPa(-1) in the normal stress mode and 12 mV kPa(-1) in the two shear stress modes. The sensor is realized using a fabrication process that is fully CMOS compatible to allow for the future integration of local processing and control circuitry. High spatial resolution robotic tactile sensing should be possible with the sensor structure, since each element is less than 300 mu m x 300 mu m in size. A description of the sensor structure, the required signal processing and mechanical characterization data is presented.