Design of scattering-enhanced visual-tactile sensor for 3D reconstruction

High-precision 3D reconstruction is essential for tactile perception in fine robotic manipulation. In response to the problems of insufficient depth sensitivity and limited durability of the existing visual-tactile sensors based on semi-transparent elastic optical response, this paper proposes a scattering-enhanced visual-tactile sensor. By introducing 0.1 wt. % TiO2 into the semi-transparent silicone layer and constructing a copper powder-based composite reflective layer, this sensor achieves significant improvements in sensitivity and durability. Compared with pure silicone, the average grayscale sensitivity increases by 74% in the 0–0.5 mm range and by 47% in the 0–1.0 mm range. Stable 3D reconstruction is achieved over 0–2.0 mm, with a depth reconstruction average absolute error of 0.0381 mm. Meanwhile, the optimized reflective layer showed only 2.1% and 4.8% average response attenuation after 5000 and 10 000 cycles, respectively, highlighting its excellent 3D imaging accuracy and long-term stability.