Characterization and modeling of a piezoresistive three-axial force micro sensor

To mimic human mechanoreceptors and give sense of touch to robots highly integrated and highly sensitive three-axial force micro sensors are required. In this paper, we present the fabrication and electro-mechanical characterization of silicon based 3D force micro sensors with piezoresistive gauges with a footprint less than 1.5 mm2. The measurements have been validated with a Finite Element Modeling (FEM). The sensor sensitivities to normal and tangential loads are about 1.03 mV/V/mN and 1.6 mV/V/mN, respectively. For such high integrated 3D force sensors these values are among the highest sensitivities reported in the literature. High linearity and low hysteresis under normal forces have also been demonstrated.