Electromechanical response of inkjet-printed multimaterial electronics under tensile strain

Per-specimen experimental records and statistical analysis for a study of how inkjet printing parameters affect the electromechanical behaviour of co-printed conductive and dielectric structures under tensile load. Specimens were fabricated on a Dragonfly IV multimaterial inkjet system (Nano Dimension) using AgCite 90072 silver nanoparticle conductive ink and 1092 dielectric ink. A conductive trace was co-printed axially inside a modified ISO 527 Type 5 tensile coupon. Trace width (72, 144, 288 um), trace thickness (10.75, 17, 34 um) and printing direction (0, 45, 90 degrees) were varied in a Taguchi L9 array. Each condition was tested with three valid replicates; a fourth specimen was produced for the 0- and 90-degree conditions, where space in the machine chamber allowed. 32 specimens are included. During each test, the axial and transverse strain fields were measured by digital image correlation (ARAMIS, 1 Hz), the load by a 10 kN cell on an Instron 5966 at 0.5 mm/min, and the trace resistance by an LCR meter at 20 Hz. All channels were filtered and resampled to 1 Hz. CONTENTS dat/: 32 files, one per specimen. Tab-separated, with a header naming the specimen and its factor levels. Columns: time (s), axial strain (%), transverse strain (%), stress (MPa), normalised resistance change dR/R0. S1_specimen_data.csv: One row per specimen: factor levels, initial conductivity, crack-onset strain, gauge factor, degradation rate, strain at the 10% resistance threshold, maximum values, whether the specimen entered the design of experiments, and the reason for every exclusion. S2a_L9_array.csv: The design. S2b_condition_means.csv Mean and standard deviation of each response per condition. S2c_regression_models.csv Main-effects and two-way-interaction models for all four responses: coefficients, standard errors, t statistics, p values, R2, adjusted R2 and the model F-test. S2d_marginal_means.csv Observed and model-adjusted marginal means. DERIVED QUANTITIES Crack-onset strain is the largest strain at which a through-origin linear fit of dR/R0 against strain stays within a 3% full-scale maximum absolute error. The gauge factor is the slope of that fit, expressed in dimensionless form. The degradation rate is the secant slope of dR/R0 against strain between crack onset and the point at which dR/R0 reaches 0.1. Initial conductivity is computed from the trace geometry and the pre-test resistance. Specimens that fractured before dR/R0 reached 0.1 have no degradation rate; these are marked in S1. One specimen (run 3, sample B) was invalidated by incorrect clamping and isreported for completeness only.