Curvature controlled microstructures for improved triaxial sensitivity in piezoelectric vibratory cantilever-type tactile sensors based on resonant frequency shift

A simplified curved structure of vibratory cantilevers has been designed and fabricated for precision improvement of triaxial tactile sensing. While the previously developed cantilever had two vibratory parts, the new one has one vibratory part and a compact hook with a small curvature radius. In tactile sensing simulation, the new structure has been expected to reduce the tactile estimation error down to 5.7%, less than a half of that of the previous one. Fabrication condition and process have been developed for the new structure having two different curvatures through optimizations of thermal treatment of the layers in the cantilever. Fabricated structure has shown the suitable curvature combination.