Cryogenic‐Assisted Electrohydrodynamic Printing of Hierarchical Microlattices With Integrated <scp>EMI</scp> Shielding, Superhydrophilicity, and Thermal Insulation

ABSTRACT Hierarchically porous composites are highly promising for advanced applications in thermal management, electromagnetic interference shielding, and filtration or separation. However, conventional fabrication methods often struggle to simultaneously achieve high structural precision, programmable macro‐architectures, and well‐controlled microporosity. To address this challenge, this study proposes a cryogenic‐assisted electrohydrodynamic printing strategy for the fabrication of hierarchical microlattices. By rapidly freezing a low‐viscosity carbon nanofiber/polyvinyl alcohol ink during high‐voltage printing, freestanding three‐dimensional microlattices with sub‐100 μm filaments are successfully fabricated. The process generates designed macropores through programmed printing paths and interconnected micropores within the filaments during subsequent freeze‐drying. This dual‐scale porous architecture endows the lightweight material with integrated multifunctionality, including superhydrophilicity for rapid oil–water separation, low thermal conductivity arising from the hierarchical porous structure, and effective electromagnetic interference shielding with absorption‐dominant behavior. The proposed strategy provides a high‐precision and designable route for manufacturing hierarchical porous composites for multifunctional applications.