Crossflow air purification across kirigami-structured menisci

The capture of particulate matters is at the heart of air pollution control for global health. Laden particles are sieved by fibrous filters, disposables that are unsustainable and cost-prohibitive for wide deployment. Here, we show that tangentially introducing polluted air across arrayed liquid menisci rising on structured kirigami effectively removes these laden particles. Approaching a meniscus, the airflow splits into two lateral branches that form counter-rotating helical vortices. This flow pattern repeats across downstream menisci, generating collective, low-speed vortices that entrain and sweep particles onto the liquid surface for irreversible absorption. This crossflow configuration prevents clogging and flux degradation, yielding a removal efficiency that increases with filter length. A 140-cm-long meniscus filter achieves a sustained filtration velocity of ∼1 m s −1 , an efficiency of 80%, and a negligible pressure drop of ∼10 Pa. This simple approach potentially promises a sustainable air purification solution for resource-poor settings.