Friction in Totally Optical Robotic Finger Oriented on Shear Force Measurement

Current developments in tactile sensors for robots have shown that they cannot be limited to the detection of normal pressure. For instance, shear force detection is an important issue in the research field oriented on the mechanical characterization. We present an innovative optoelectronic PDMS-Au tactile robotic sensor based on the concept of light coupling in a nanocomposite material due to applied pressure. The friction of two tip layouts is investigated by means of a tribometer. A one-to-one almost inversely linear relationship between the optical transmittivity and the coefficient of friction is observed. This property of the sensor together with its low cost makes it very interesting in those applications where the detection of surface inhomogeneities is the key issue.