Strain Mapping Inkjet-Printed Resistive Sensors Array

Inkjet-printing is a promising low-cost fabrication technique capable of depositing functional materials with micrometer resolution, making this technique attractive for the fabrication of deformable sensors. Despite all the possible promising applications, no examples of inkjet-printed strain sensors array able to map substrate surface deformation have been proposed yet. On the base of these premises, it is here presented the development and characterization of an all-inkjet-printed resistive strain sensors array, highlighting criteria adopted in the design phase. Initially, the strain sensing behavior of the printed CNTs percolation matrix was investigated by fabricating and electromechanically characterizing a single sensor. The proposed single sensor featured a sensitivity of 7.2 +/- 2 up to 2.5% strain, demonstrating that the proposed sensing material is suitable for the fabrication of an inkjet-printed strain sensors array. Moreover, the fabricated sensors array was characterized through a confined electromechanical tensile test in which a non-homogeneous strain state was applied. Results showed the mapping capability of inkjet-printed deformable sensors array that is able to measure different local strains on the substrate surface. This work paves the way for using inkjet-printing technique for the realization of sensors with a larger number of interesting applications.