Fig. 3: Particle size distribution and sedimentation dynamics in LS-ACA.

a SEM image of LS-ACA with low (LLM, 64.3 wt%) and high (HLM, 90.0 wt%) concentrations of LMPs. b Size distribution curves of LMPs according to LM concentration. c Measured lateral resistances between two microelectrodes with various gap widths (ranging from 6.6 to 26.4 μm) using low (LLM) and high (HLM)-concentration LMPs in LS-ACA. The inset images show that for LLM, LMPs with an average size of 1.7 μm are too small to bridge a 6.6 μm electrode gap, thus maintaining lateral insulation. In contrast, in the HLM condition, LMPs exceeding 6.6 μm form conductive bridges across the gap, resulting in lateral conduction. d SEM images of large-area high-concentration (HLM) and low-concentration (LLM) LS-ACA. To measure the number of particles, the images are processed using ImageJ software. The images are modified so that only particles with a size of 1 μm or larger are counted. e, f The red numbers in (d) (right), indicating particle counts analyzed via ImageJ, are assumed to represent the centers of the particles. All possible combinations of the detected center coordinates are used to calculate center-to-center distances. The measured distances are then visualized in the form of a histogram. g–i Comparison of theoretical and experimental particle size distributions of low concentration (37.5 wt%), LLM (64.3 wt%) and HLM (90.0 wt%). LMP sizes in LS-ACA are measured at different time points: immediately after fabrication (0 days), after 7 days and 14 days. The number of particles used for plotting the dispersion graph is as follows: 0 days (low concentration: n = 30, LLM: n = 30 and HLM: n = 30), 7 days (low concentration: n = 30, LLM: n = 25 and HLM: n = 9), and 14 days (low concentration: n = 27, LLM: n = 16 and HLM: n = 4), indicating a gradual decrease in the number of LMPs over time due to sedimentation.