Biomimetic Porous Hygroscopic Monolith with Vertically Aligned Channels by 3D Printing for Rapid Dehumidification and Regeneration

Abstract Humidity control is crucial for applications such as green building design and equipment preservation. However, traditional dehumidification methods often suffer from limitations such as high energy consumption, poor scalability, or inefficient moisture transfer. Herein, inspired by the hierarchical porous microstructure in trees, a biomimetic sorbent monolith with vertically aligned channels and robust structure is fabricated through direct‐ink‐writing 3D printing technology for sorption‐based dehumidification. Owing to abundant pore structure ranging from millimeter to micrometer scales, the monolith exhibits fast water uptake and facile regeneration. This study investigates its potential to achieve rapid dehumidification under a wide relative humidity (RH) range of 60–90%. One piece of monolith reduces the RH of a space 6750 times its own volume from 90% to below 60% in 25 min and maintains it with ultra‐low energy consumption. Besides, the monolith fabricated by 3D printing is easy to be scaled up with low costs meeting the demands of large‐scale production and practical deployment. It is expected that the monolith may fulfill diverse humidity needs while broadening the applications of 3D printing technology.