Hall-effect devices as strain and pressure sensors

Abstract It was found that the offset voltage of the Hall-effect device is very sensitive to mechanical strain without application of a magnetic field. This effect is called the Kanda effect. An explanatory model of the effect is suggested. It is a square bridge circuit consisting of our stress-variable resistances. Each resistance is connected to the middle points of the neighbouring sides. The output is proportional to the difference between the longitudinal and transverse piezoresistance coefficients. The model is confirmed by the experiments. An IC strain sensor using this effect is proposed. The design analysis of silicon diaphragm pressure sensors using the Kanda effect is considered for square, rectangular and circular diaphragms. The potential distribution resulting from conductivity distribution is obtained by the finite-difference method. The relaxation method is used for numerical calculation. This pressure sensor is attractive for miniature biomedical applications.