3D printing a cellular channel sponge for high-efficiency liquid collection and solar evaporation

Rapid liquid collection plays an important role in many environmental and health-related applications, such as oil spill cleanup and clinical sampling. However, the low-cost and the energy-effective liquid absorbing remain a grand challenge, especially for viscous liquids. Here, by mimicking, scaling up, and rationally designing the microchannels of animals' cornea, a sponge with 3D-cellular microfluidic channels, which has a large liquid absorption coefficient, was proposed and prepared using 3D printing. Compared with the sponge with random pores, the 3D-printed sponge has both faster absorption speed and larger capacity due to controllable channel size, low tortuosity, and large porosity of the cellular channels. Moreover, by combining with the photothermal effect, the 3D-printed sponge exhibits superior absorption performance for highly viscous curd oil under the irrigation of sunlight. The 3D printing endowed topographic surface also makes the 3D-printed sponge as the promising candidate for solar water evaporation. The design of sponge with cellular channels shows great potential in eco-friendly, low-cost, and high-efficiency collection of liquids with various viscosities and solar water evaporation. © 2025 Elsevier B.V.