The Spinning Transverse Voltage Method for the Extraction of Compensated sxx - syy and sxy Stresses from a Single Four-Contact Sensor

Abstract:
This paper describes a method to extract two components of the stress tensor from the response of piezoresistive devices with only four contacts. Like in spinning-current Hall sensors, the device is subjected to a current with continuously rotating effective direction. Simultaneously, the potential drops across two orthogonal pairs of opposite contacts are measured as a function of the current direction. From these angle-dependent output signals, thermoelectric and magnetic influences are eliminated by a Fourier transform while the two mechanical stresses (sigmaxx - sigmayy) and sigmaxy are straightforwardly extracted.