“…Over the past few decades, a rapid progress has been achieved in the development of gas–liquid two‐phase flow, especially the slug flow, for its numerous and diverse applications in the chemical reaction, 1–3 gas absorption, 4–6 heat transfer, 7,8 crystallization, 9,10 and so on. Importantly, the gas–liquid slug flow in microdevices greatly promotes the mass transfer efficiency owing to the large specific surface area and circulation flow inside slugs, which has attracted considerable attention in recent years 11,12 .…”