A silicon-based tactile sensor for finger-mounted applications

Presents a silicon-based force sensor packaged in a flexible package and describes the sensors performance on human subjects. The sensing element consists of a circular silicon diaphragm (200-μm thick with a 2-mm radius) over a 10-μm sealed cavity with a solid Torlon dome providing force-to-pressure transduction to the diaphragm. Two dome heights (0.5 and 1.5 mm) were compared. The sensor with the taller dome showed improved sensitivity. Dynamic calibration and tracking experiments are performed with the sensor mounted on the dominant thumb of 5 human subjects. Both force and loading direction are statistically significant (P<0.05). Subject variability accounted for 8.7% of the variance, while loading direction accounted for 1.9% of the variance. Average errors for the tracking experiment range from -2.8 to 1.0 N and are subject dependent. Three out of 4 subjects showed increasing negative error with increasing load.