  We present an investigation of inkjet printed strain gauges based on
two-dimensional (2D) materials. The technology leverages water-based and
biocompatible inks to fabricate strain measurement devices on flexible
substrates such as paper. We demonstrate that the device performance and
sensitivity are strongly dependent on the printing parameter (i.e., drop-
spacing, number of printing passes, etc.). We show that values of the Gauge
Factor up to 125 can be obtained, with large sensitivity (>20%) even when small
strains (0.3%) are applied. Furthermore, we provide preliminary examples of
heterostructure-based strain sensors, enabled by the inkjet printing
technology.
