Temperature-compensation of 3D-printed Polymer-based Strain Gauges

摘要

With the advent of 3D printing and the increasing list of available materials, various functional devices canbe printed for low-cost, rapid prototyping. In particular, 3D-printed strain gauges show promise in multipleapplications such as robotics and structural health monitoring. However, characterization and compensation ofthe thermal dependence of such strain gauges have been limited in the literature. In this work the temperaturedependentresistive behavior is characterized for strain gauges printed with a commercially available lament,conductive PLA (Polylactic Acid), which has also shown other desirable uses such as stiu000bness-tuning for softrobots. The relationship between temperature and resistance is shown to be hysteretic. Several compensationmethods (Temperature-based algebraic subtraction, Material-based algebraic subtraction, and a Wheatstonebridge-based method) are explored to mitigate the effect of temperature and show the material's feasibility asa strain gauge. The compensation methods are quantitatively compared by calculating the mean squared errorbetween the predicted and the ground truth strain values. It is shown that the Wheatstone bridge-based methodprovides the best compensation. This method achieves average errors of less than 10% and a maximum errorless than 20% over a working range of approximately 15,000 microstrain (0.15% strain) over a range 30 to 40℃.