Low-interference sensing electronics for high-resolution error-correcting biomechanical ground reaction sensor cluster

This paper presents a low-interference and low power sensing electronics design for a high-resolution error correcting biomechanical ground reaction sensor cluster (GRSC) developed for improving inertial measurement unit (IMU) positioning resolution and accuracy. The GRSC is composed of 13 × 13 sensing nodes, which can measure dynamic ground forces, shear strains, and sole deformation associated with a ground locomotion gait. The integrated sensing electronics consist of a front-end multiplexer that can sequentially connect individual sensing nodes in a GRSC to a capacitance-to-voltage converter followed by an ADC, digital control unit, and driving circuitry to interrogate the GRSC. The sensing electronics are designed in a 0.15 μm CMOS process and occupy an area of approximately 3 mm² with an expected resolution of 10-bits and 14-bits for the z-axis pressure sensing and the x and y-axes shear strain sensing, respectively, while dissipating a DC power less than 2 mW from a 3V supply.