The development of multifunctional artificial cilia may inspire a new generation of intelligent biomimetic microdevices and microfluidic systems, but remains a great challenge. Here, self-adaptive magnetic photonic nanochain cilia arrays (SMPNCAs) capable of achieving real-time and in situ visual microenvironment detection and self-adaptive fluid pumping are shown. By combining magnetic assembly and UV-assisted hydrogen bond-guided template polymerization in printing, SMPNCAs consisting of individual 1D periodic structure of magnetic nanoparticles encapsulated in pH-responsive hydrogel shells, as an example, are demonstrated to be printed on a glass substrate with defined patterns in one step. The as-printed SMPNCAs exhibit real-time adjustable interparticle distance (lattice constant) and total length in response to the reversible volume change of the hydrogel shell with the pH value of the pumped fluids. Consequently, they can sense the surrounding pH variation in real time by in situ displaying different diffracted color, and pump directional flows with self-adaptive flow velocity under a rotating magnetic field. Benefiting from the integration of the facile, robust printing fabrication, structure-color-based fast sensing, and self-adaptive fluid pumping, the SMPNCAs that are developed here promise a significant advancement in biomimicry and microfluidic systems.

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Molecular‐sieving membranes from metal–organic frameworks (MOFs) are promising candidates for separating olefin/paraffin mixtures, a critical demand in sustainable chemical processes and a grand challenge in molecular separation. Currently, the inherent lattice flexibility of MOFs severely compromises their precise sieving ability. Here, a proof‐of‐concept of “alloy” membranes (AMs), which are fabricated by incorporating quaternary ammonium (QA)‐functionalized covalent organic frameworks (COFs) into a zeolitic imidazolate framework‐8 (ZIF‐8) matrix is demonstrated. The Coulomb force between the COFs and the ZIF‐8 restricts the linker rotation of the ZIF‐8, generating a distinct alloying effect, by which the lattice rigidity of ZIF‐8 can be conveniently tuned through varying the content of the COFs, similar to the flexible‐to‐rigid transition in aluminum alloy manufacturing. Such an alloying effect confers the AM's superior propylene/propane separation performance, with a propylene/propane separation factor surpassing 200 and a propylene permeance of 168 GPU. Hopefully, the AMs concept and the concomitant alloying effect can update the connotation of mixed matrix membranes and stimulate the re‐envisioning about the design paradigm and development of advanced membranes for energy‐efficient separations.

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