Design of magnetostrictive tactile sensor for depth detection

Purpose This paper aims to design a magnetostrictive tactile sensor for surface depth detection. Unlike the human finger, although most tactile sensors have high sensitivity to pressure, they cannot detect millimeter-level depth information on the surface of objects precisely. To enhance the ability to detect surface depth information, a piezomagnetic sensor combining inverse magnetostrictive effect and bionic structure is developed in this paper. Design/methodology/approach A magnetostrictive tactile sensor based on Galfenol [(Fe 83 Ga 17 ) 99.4 B 0.6 ] is designed and studied for surface depth measurement. The optimal structure of the sensor is determined by experiment and theory. The test platforms for static and dynamic characteristics are set up. The static and the dynamic sensing performance of the sensor are studied experimentally. Findings The sensor can detect 0–2 mm depth change with a sensitivity of 91.5 mV/mm. A resolution of 50 µm can be achieved in the depth direction. In 50 cycles of loading and unloading tests, the maximum error of the sensor output voltage amplitude is only 2.23%. Originality/value The sensor can measure the depth information of object surface precisely with good repeatability through sliding motion and provide reference for object surface topography detection.