A filter inspired by deep-sea glass sponges for oil cleanup under turbulent flow

Oil spill disasters lead to widespread and long-lasting social, economical, environmental and ecological impacts. Technical challenges remain for conventional static adsorption due to hydrodynamic instability under complex water-flow conditions, which results in low oil-capture efficiency, time delay and oil escape. To address this issue, we design a vortex-anchored filter inspired by the anatomy of deep-sea glass sponges (E. aspergillum) by mimicking their exceptional skeletal features and filter-feeding patterns. Results demonstrate that the vortex-anchored filter can retain external turbulent-flow kinetic energy in low-speed vortical flow with small Kolmogorov microscale (85 μm) in the cavity of skeleton, leading to enhanced interfacial mass transfer and residence time by physical field synergy. It improves hydrodynamic stability by reducing Reynolds stresses in nearly quiescent wake flow. The vortex-anchored filter can realize >97% capture of floating, underwater and emulsified oils stably at Reynolds numbers ranging from subcritical to supercritical regimes. This study not only highlights the importance of vortex-anchored mechanism in enhancing interfacial mass transfer and hydrodynamic stability during oil capture beyond previously known benefits of increased residence time, but also represents a paradigm shift to advance biophysically inspired strategies for in-situ, dynamic and robust cleanup of spilled oil, environmental remediation and resource recovery.