Design of a Biomimetic Spherical-End Tool Based on Gastropod-Shell Surface Microstructures and an Investigation of its Polishing Performance

To improve stress-distribution uniformity and reduce wear during polishing, a biomimetic flexible polishing tool was developed by incorporating microstructured surface features inspired by the gastropod shell. A biomimetic flexible polishing tool was first geometrically modeled, and then the tool–workpiece contact was analyzed in the elastic polishing regime using Preston’s material removal equation to elucidate stress transmission and contact deformation mechanisms. An Abaqus finite-element model of the elastic tool–workpiece contact was subsequently established to compute tool and workpiece stress fields and contact-area fraction during polishing. The biomimetic tools were fabricated by curing silicone rubber mixed with carbon nanotubes. Polishing validation was performed on a small CNC platform using quartz glass under the parameters α=15°, ap=2mm, and w=30r/s. Results indicate that the biomimetic tool incorporating gastropod-shell microstructures increases the machining contact area by up to 48.60% relative to a conventional tool, and after t=30 min of polishing the surface roughness Ra decreased from 1.019μm to 76nm. These outcomes demonstrate that the biomimetic microstructured flexible tool effectively improves contact stress uniformity and enhances surface- processing accuracy for quartz glass.