Design and Optimization Array of Micropillar Structures for Enhanced Evaporative Cooling of High-Powered Electronics

Seeking maximum evaporative heat transfer, here we report the numerical optimization of an array of non-axisymmetric droplet shapes confined on hollow micropillars. Different shapes of droplets exhibit very different interfacial mass transport features, based on their different perimeter-to-area ratios and meniscus curvatures. Most recently, we have shown that, compared to spherical droplets, microdroplets confined on triangular micropillars can have up to a 71% higher heat transfer coefficient at a substrate temperature of 98°. Furthermore, to maximize the heat transfer coefficient, we optimized the shape of a triangular micropillar. In this study, building on our previous work, we use particle swarm optimization to identify the arrangement of arrays of micropillars that maximizes non-axisymmetric droplet evaporation. The optimized array of non-axisymmetric droplets, confined on pseudo-triangles, has a 3.5% higher heat transfer coefficient than an unoptimized array of reference non-axisymmetric pseudo-triangles. Compared to circular droplets on an orthogonal arrangement of micropillars, it has a 14.1% higher heat transfer coefficient.