Strain-based multimode integrating sensing for a bridge-type compliant amplifier

This paper presents a compact strain-based multimode sensing approach, in which sensing units are monolithically combined in a compound compliant bridge-type amplification mechanism. Under the same strain gauges configuration, this approach can realize different-mode precision sensing for output displacement, input displacement and input force measurement. Based on elastic beam theory and the modified geometric analysis method, an output/input displacement-sensing model only relating to the moment, and an input force-sensing model only relating to the axial force are analytically derived. These analytic sensing models indicate their good linear sensing performance, which is validated experimentally. The related experiments and analysis indicate that it has excellent heat-insulating performance, and their measurement accuracies can reach the tens of nanometer level for displacement sensing and the sub-Newton level for force sensing in void output loads, which fulfill the requirements of most of the nano-positioning stages.