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Although many methods have been developed to create porous structures within polyelectrolyte films, it remains a challenge to conveniently define the spatial distribution of these structures. Herein, a simple, universal strategy with a high flexibility in programming porous regions throughout polyelectrolyte films is reported. This strategy is performed with the aid of laser scanning and the emergence of porous regions precisely tails after the moving path of laser beams. Quite different from previous strategies, the pore‐forming mechanism relies on laser‐triggered generation of gas to foam the films, which can be regulated by the content of photo‐sensitive groups, the intensity of laser beams, and the supramolecular interactions between polyelectrolyte chains. A prerequisite to succeed the foaming of polyelectrolyte films is to irradiate them under water, where the mobility of polyelectrolytes is activated to accommodate the pore formation within the films. Although many pore‐forming mechanisms involve aqueous systems, the porous structures here can be well preserved during drying procedures, which is hardly realized for conventional methods due to the formation of capillary pressure. The resulting polyelectrolyte films with patterned porosity can be quite useful in many fields, including but not limited to information display, surface wettability, and cell behavior manipulation. [ABSTRACT FROM AUTHOR]

Although many methods have been developed to create porous structures within polyelectrolyte films, it remains a challenge to conveniently define the spatial distribution of these structures. Herein, a simple, universal strategy with a high flexibility in programming porous regions throughout polyelectrolyte films is reported. This strategy is performed with the aid of laser scanning and the emergence of porous regions precisely tails after the moving path of laser beams. Quite different from previous strategies, the pore‐forming mechanism relies on laser‐triggered generation of gas to foam the films, which can be regulated by the content of photo‐sensitive groups, the intensity of laser beams, and the supramolecular interactions between polyelectrolyte chains. A prerequisite to succeed the foaming of polyelectrolyte films is to irradiate them under water, where the mobility of polyelectrolytes is activated to accommodate the pore formation within the films. Although many pore‐forming mechanisms involve aqueous systems, the porous structures here can be well preserved during drying procedures, which is hardly realized for conventional methods due to the formation of capillary pressure. The resulting polyelectrolyte films with patterned porosity can be quite useful in many fields, including but not limited to information display, surface wettability, and cell behavior manipulation. [ABSTRACT FROM AUTHOR]

The emergence of lamellar nanofluidic membranes offers feasible routes for developing highly efficient, mechanically robust, and large‐scale devices for osmotic energy harvesting. However, inferior ion permeability associated with their relatively long channels limits ionic flux and restricts their output performance. Herein, a superstructured graphene oxide membrane is developed to allow programmable topological variation in local geometry and contain laminar spaces inside. Such deliberate design offers excess specific area as well as nanofluidic channels to modulate transmembrane ionic transportation while concomitantly retaining similar nanoconfined environment in contrast to planar ones, leading to considerable enhancement of ionic permeability without compromising selectivity. This can be highly favorable in terms of osmotic energy harvesting, where the superstructured membranes offer a power output much higher than those of conventional planar ones. Besides, the superstructure design also endows the resulting membranes with benign biofouling resistance, which can be crucial to their long‐term usage in converting osmotic energy. This study highlights the importance of membrane topographies and presents a general design concept that could be extended to other nanoporous membranes to develop high‐performance nanofluidic devices. [ABSTRACT FROM AUTHOR]