Self‐Driving Underwater “Aerofluidics”

Abstract

Abstract Here, the concept of “aerofluidics,” in which a system uses microchannels to transport and manipulate trace gases at the microscopic scale to build a highly versatile integrated system based on gas‒gas or gas‒liquid microinteractions is proposed. A kind of underwater aerofluidic architecture is designed using superhydrophobic surface microgrooves written by a femtosecond laser. In the aqueous medium, a hollow microchannel is formed between the superhydrophobic microgrooves and the water environment, which allows gas to flow freely underwater for aerofluidic devices. Driven by Laplace pressure, gas can be self‐transported along various complex patterned paths, curved surfaces, and even across different aerofluidic devices, with an ultralong transportation distance of more than 1 m. The width of the superhydrophobic microchannels of the designed aerofluidic devices is only ≈42.1 µm, enabling the aerofluidic system to achieve accurate gas transportation and control. With the advantages of flexible self‐driving gas transportation and ultralong transportation distance, the underwater aerofluidic devices can realize a series of gas control functions, such as gas merging, gas aggregation, gas splitting, gas arrays, gas‒gas microreactions, and gas‒liquid microreactions. It is believed that underwater aerofluidic technology can have significant applications in gas‐involved microanalysis, microdetection, biomedical engineering, sensors, and environmental protection.

Keywords

• femtosecond laser
• gas transportation
• Laplace pressure
• superhydrophobicity
• underwater aerofluidics