A tactile sensor for simultaneous measurements of 6-axis force/torque and the coefficient of static friction

We propose a new design for a tactile sensor that simultaneously measures 6-axis force/torque and the coefficient of static friction, which will enable robotic fingers to handle a slippery object while preventing both translational and rotational slips. The sensor consists of internal and external substrates, internal and external elastomers and normal/shear stress sensor chips. The sensor chips are arranged on the substrates and embedded in the elastomers to measure the deformation of the elastomers. The coefficient of static friction is estimated from the normal and spread deformations of the external elastomer. The 6-axis force/torque values are estimated from the normal, shear and torsional deformations of the internal elastomer. We evaluated the sensor responses when the sensor came into contact with various objects with different coefficients of static friction. We confirmed that the coefficient of static friction and the 6-axis force/torque changes were able to be estimated from the sensor outputs.