Thread based Resistive Sensor for Tactile and Slippage Detection in Smart Bionics

One of the remarkable features of the human tactile system is the perception of slippage over a diverse range of object dimensions, weights, shapes, textures, and stiffness. Advanced prosthetics strive for more natural and intuitive performance, hence slippage anticipation and prevention being indispensable for an artificial hand. Numerous sensor and circuit topologies have been used in the state-of-the-art. Multi-modal sensor integration for static and dynamic measurements, complex design, wearability, sensitivity, hysteresis, and cost are still the significant challenges faced. In this work, a simple, low-cost, flexible thread-based resistive strain/force sensor is fabricated and interfaced with a current source excitation-based resistance measurement circuit. The sensor exhibits excellent performance for slip detection by showing selectivity to the static and dynamic measurements corresponding to the event of initial object contact and slippage instances, respectively. The proposed circuit topology promises better sensitivity, resolution, and baseline resistance compensation, leveraging the system’s effectiveness for slippage detection. Experimental result shows the sensor can measure a displacement as small as 0.1 mm. This method can generate further control actions for slippage prevention thereafter.