Miniaturized Six-Degree-of-Freedom Force/Moment Transducers for Instrumented Teeth With Single Sensor Chip

This paper reports on a novel force/moment transducer small enough to replace the root of an artificial tooth. Its dimensions of 4.5 mm in diameter and 16.4 mm in height are identical to the former state-of-the-art design. However, the new design requires a significantly reduced assembly effort and imposes lower demands on the external read-out periphery. The latter improvement facilitates the simultaneous operation of a larger number of force/moment transducers. The novel design was optimized using the finite-element analysis, whose results are experimentally validated. The new design and the former state-of-the-art design are extensively tested with the same test procedure for ranges of ±3 N and ±30 Nmm. The measurement accuracies are measured to be 10, 23, and 64 mN for the forces f
_x
, f
_y
, and f
_z
, respectively, and 161 × 10
^-3
Nmm, 302 × 10
^-3
Nmm, and 42 × 10
^-3
Nmm for the moments m
_x
, m
_y
, and m
_z
. Despite the simpler assembly effort and device handling, the accuracy is better or at least close to former designs. Especially, the more critical force measurements are significantly improved. Long-term stability tests show only little change in measurement performance of the two designs in time.