In Situ Printing of Conductive Poly Lactic Acid Strain Sensors Embedded into Additively Manufactured Parts

Abstract

This paper presents a technique to additively manufacture a strain sensor into 3D printed parts in order to measure internal strains. Carbon filler material embedded into a base thermoplastic produces a filament that can be extruded using the most common additive manufacturing technology, fused deposition modeling, to produce a plastic geometry that has the ability to conduct electricity. Strain sensors produced using this material operate similarly to commercial strain gauges, i.e., as the part undergoes a change in strain, there will be a change in the measured electrical resistance of the sensor. This paper discusses the various parameters explored and calibration efforts to obtain a working strain sensor.