Characterization of mineralized membranes with zig-zag microchannels.(A, C) SEM images of mineralized structures grown on ELR membranes with zig-zag Channel (2, 2) patterns aligned at 45°, 90°, and 135° corner angles. (B) Graph depicting the relation between the aspect ratio of the mineralized structures and the corner angles of the zig-zag patterns. Solid bars correspond to aspect ratio of visual distance and striped bars correspond to aspect ratio of growing distance. (D) SEM images of the mineralized structures growing along the channel directions and guided by the zig-zag patterns (with 90° and 135° corner angles) over a millimeter length scale. Minor distortions in the channel geometry appeared on zig-zag patterns (highlighted by arrows) in the presence of the mineralized structures, suggesting the presence of stresses being generated by the growing nanocrystals.