Biomimetic Microfluidic Pumps for Selective Oil–Water Separation

Abstract Addressing the challenges posed by oil pollution from both domestic and industrial sources—which contributes to energy waste and environmental degradation—is critical. Here, a new, efficient, and sustainable oil/water separation system is presented using biomimetic spring microchannels created through precise projection micro‐stereolithography‐based 3D printing technique. This innovative system allows for the swift separation of mixed oil and water phases into distinct and pure streams, achieving a high separation flux of up to 292.5 L m −2 h −1 . The separation efficiency, consistently maintained over 99%, leverages the synergistic effects of surface wettability and molecular polarity to handle multiple oils with varying densities and surface tensions. Moreover, the biomimetic microchannels precise capturing of the oil/water interface and offer flexibility to initiate separation by prefilling the channels with either oil or water. Furthermore, these microchannels effectively prevent clogging, ensuring sustained performance. A significant enhancement is also demonstrated in separating crude oil from water by solar irradiation to reduce its viscosity, with a notable separation rate of 22.5 L m −2 h −1 for individual channels. The findings underscore the potential of 3D bionic functional spring microchannels for selectively separating a wide range of oil‐water mixtures with exceptional efficiency.