Chemically active droplets exhibit complex avoiding trajectories. While heterogeneity is inevitable in active matter experiments, it is mostly overlooked in their modeling. Exploiting its geometric simplicity, we fully resolve the head-on collision of two swimming droplets of different radii and demonstrate that even a small contrast in size critically conditions their collision and subsequent dynamics. We identify three fundamentally different regimes. The resulting high sensitivity of pairwise collisions is expected to profoundly affect their collective dynamics.

中文翻译：

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弹跳，追逐或暂停：活动液滴的非对称碰撞

化学活性液滴表现出复杂的回避轨迹。尽管异质性在活性物质实验中是不可避免的，但在其建模中却常常被忽略。利用其几何上的简单性，我们完全解决了两个半径不同的游泳液滴的正面碰撞，并证明即使是很小的反差也会严重影响其碰撞和随后的动力学。我们确定了三种根本不同的制度。预期成对碰撞的高灵敏度将深刻影响其集体动力。