Detection analysis of small notches damages using a new tactile optical device

In this paper, the experimental application of a new class of optical pressure sensors based on polydimethylsiloxane (PDMS)-Au aimed at detecting and classifying millimetric surface damages of mechanical components is developed. The device consists of a tapered bended optical fiber, where an optical signal goes across, embedded into a PDMS-gold nanocomposite material (GNM). The sensor is automatically moved for the optical scanning of surfaces by means of a high-accuracy servo motor. After moving and positioning the detector, the sensor output data are acquired and processed in such a way as to pinpoint small notches on a beam. Notches of different lengths to within a few millimeters were scanned to test the realized device capability in recognizing and characterizing very small defects. The experimental results are very encouraging; they exhibit high sensitivity and inspire the use of the sensor in multifarious applications of robotics.