Fig. 2: Illustration of print methodologies and analysis of printed samples for embedding bulk-metal conductive traces in polymer layers.

a–c Illustration of PPM and PMP methodology, respectively, for printing conductive traces in polymer channels. b–d Microscopic images of the sample at the cross-section planes of a sample printed with PPM and PMP methodology, respectively, with empty spaces covered by epoxy highlighted in light green. e, f Comparison of metal infill percentages in polymer channels for PPM and PMP methodologies. The central line inside the “violin” indicates the mean, while the width of the “violin” represents the kernel density estimate of the data. Error bars extending from each data point indicate the variability around the mean, with the length of the error bars corresponding to one standard deviation from the mean. g, h Microscopic images of conductive trace embedded in polymer viewed after cross-section grinding highlighting conformal printing and metal fusion, respectively. i Infill percentage for PMP-printed samples before and after the thermal cycling procedure. The central point inside the “violin” indicates the mean, while the width of the “violin” represents the kernel density estimate of the data. The error bars correspond to the standard deviation from the mean. j Resistance measured on embedded conductive traces for PMP-printed samples before and after the thermal cycling procedure. The central line inside the “violin” indicates the mean, while the width of the “violin” represents the kernel density estimate of the data. The error bars correspond to the standard deviation from the mean.