Calibration method for MEMS 3D micro-tactile force sensor

A precise calibration method for micro electro mechanical system (MEMS) 3D micro-tactile force sensors was proposed in this paper. Standard micro-force signal was obtained from bending cantilever and the calibration error was compensated by measuring the micro displacements of the probe resulting from elasticity of the sensitive beam of the sensor. Calibration system for MEMS 3D micro-tactile force sensor was set up, in which the elasticity coefficient of cantilever was calibrated by precision balance and linearized signal conditioning circuit was designed to make the weak voltage signal obtained from the sensor more suitable for measurement. In the calibration process, effect of the micro displacement of the probe on calibration precision due to elastic deformation of the sensor sensitive beam was taken into consideration. Displacement characteristics of probe was measured with high-precision nano-measuring machine (NMM), with which the main calibration error from mechanics property coefficients of the sensor was compensated. Finally the mechanics property output equations of the sensor were established based on the initial output voltages of the sensor and its mechanics property coefficients.