Inkjet-printed electronics is a low-cost option for large-scale production. To avoid manufacturing defects, recent research has considered design constraints, such as Laplace and proximity conflicts, decomposed the layouts into different layers, and printed them sequentially. The state-of-the-art work reduced the manufacturing time by optimizing the number of layers and drying time. In this work, we aim to enhance manufacturing efficiency from a new angle, concurrently optimizing the printing time and the layout decomposition of inkjet-printed electronics. We propose an integer linear programming formulation and a dynamic programming algorithm to determine layout decomposition and layer assignment and to estimate the total printing time by carefully considering printing characteristics and design constraints. Experimental results demonstrate significant reductions in overall printing time, leading to improved fabrication efficiency.

Inkjet-printed electronics has attracted considerable attention for low-cost mass production. High-density inkjet-printed designs can benefit from printing and drying in batches to avoid defects due to undesired ink redistribution and ink merging. The state-of-the-art approach decomposes the design into small objects, assigns the objects to different layers to be printed in different iterations, and minimizes the number of layers to reduce the number of iterations. However, it overlooks the differences in the printing and drying time between different layers and thus cannot properly model the impact of different layer assignment solutions on the manufacturing cycle time. In this work, we propose a row-based printing model that simulates the inkjet-printing mechanism and an integral Gaussian drying model that evaluates the local evaporation rate to approximate the printing and drying process of inkjet-printed manufacturing. Based on these models, we propose a mixed-integer-linear programming (MILP) method called the manufacturing model to minimize the manufacturing cycle time and avoid defects by optimally assigning objects to different iterations to be printed and dried in batches. Experimental results confirm that, compared with the preliminary work, manufacturing using our optimized solutions required up to 42.7% less time.

Inkjet-printed electronics have attracted considerable attention for low-cost mass production. To avoid undesired device behavior due to accidental ink merging and redistribution, high-density designs can benefit from layering and drying in batches. The overall manufacturing cycle-time, however, now becomes dominated by the cumulative drying time of these individual layers. The state-of-the-art approach decomposes the whole design, arranges the modified objects in different layers, and minimizes the number of layers. Fewer layers imply a reduction in the number of printing iterations and thus a higher manufacturing efficiency. Nevertheless, printing objects with significantly different drying dynamics in the same layer leads to a reduction of manufacturing efficiency, since the longest drying object in a given layer dominates the time required for this layer to dry. Consequently, an accurate estimation of the individual layers' drying time is indispensable to minimize the manufacturing cycle-time. To this end, we propose the first Gaussian drying model to evaluate the local evaporation rate in the drying process. Specifically, we estimate the drying time depending on the number, area, and distribution of the objects in a given layer. Finally, we minimize the total drying time by assigning to-be-printed objects to different layers with mixed-integer-linear programming (MILP) methods. Experimental results demonstrate that our Gaussian drying model closely approximates the actual drying process. In particular, comparing the non-optimized fabrication to the optimized results demonstrates that our method is able to reduce the drying time by 39%.