The Boeing Company
Stress sensor

Abstract:

A stress sensor is provided, including a substrate and a bridge circuit disposed thereon. The bridge circuit is coupled between an output node and a ground node. The bridge circuit includes a first branch and a second branch, the first having a first resistor, R1, having a first orientation and coupled to a tuning resistor, Rtune, at a first intermediate node. The second branch includes a second resistor, R2, having a second orientation that is different from the first orientation, and coupled to a variable resistor, Rvar, at a second intermediate node. The bridge circuit includes an amplifier having a positive input terminal coupled to the second intermediate node, and a negative input terminal coupled to the first intermediate node. The amplifier generates a voltage output at the output node as a function of mechanical stress applied to the substrate. Rvar is non-linearly tunable based on the voltage output.