An artificial skin based on optoelectronic technology

This work proposes an artificial skin composed by independent sensing modules, able to estimate both normal and shear contact force components. Each sensing module consists of four couples (taxels) of infrared Light Emitting Diodes and a Photo-Detectors, covered by a silicone layer that transduces the external force in a mechanical deformation. The applied force vector is estimated as a suitable combination of the four voltage signals measured by the four receivers. A complete prototype, with a 6 × 6 matrix of sensing modules, has been realized, characterized and tested. The prototype is able to discriminate multiple contact areas and to estimate the force resultants for each contact area. Envisaged applications are safe physical human-robot interaction, where contact forces over large distributed areas can occur. The use of a dedicated distributed sensor for measuring the contact force vectors is aimed at overcoming current methods based on the use of dynamic models and joint torque measurements.