Piezoresistive CMOS sensor for the localized measurement of five independent stress components

This paper reports the development and characterization of a highly integrated polyvalent CMOS stress sensor detecting five linearly independent, temperature compensated components of the six-dimensional stress space. The sensor has a footprint of only 29×29 ¿m². It combines different piezoresistance sensors to detect the three shear stresses, the in-plane normal stress difference, and a sum of the three normal stresses. The sensitivities of five sensing modes are characterized by applying in-plane normal and shear stresses, out-of-plane shear stresses, and temperature changes. The sensor performance is demonstrated by monitoring the hardening of an epoxy resin.