Strain-based output/input sensing cell integrated within a compliant bridge-type mechanism

This paper presents a compact design, modeling and analysis of strain-based output/input sensing cell integrated within a compliant bridge-type amplifier. Through extending the length of the leaf hinges, the output displacement sensor, input displacement sensor and input force sensor are embedded in the new amplifier in a same strain-gauges configuration. Based on the symmetric configuration of the strain gauges, the output/input displacement sensing models and the input force model are analytically derived in a simplified geometric analysis method, and the correspondent strain-bridge circuits are presented. The static FEM analyses are implemented at the situation of being with output loading and without output loading. The analytic sensing models and the results of the static FEM simulation demonstrate their excellent linearity especially without output loading. More importantly, the presented displacement and force sensors have a limited performance with output loading, but excellent performance without loading and with lower output loading while in high input forces.