FIG. 4.

SEM images and samples of Y-shape ESBM fabricated at different concentrations of NaAlg when the CaCl₂ concentration was fixed at 270 mM. (a) and (b) Double channel part of the Y-shape structure fabricated at 3% NaAlg and the channel after trimming. (c) and (d) Double channel part of the Y-shape structure fabricated at 4% NaAlg and the channel after trimming. (e) and (f) Double channel part of the Y-shape structure fabricated at 5% NaAlg and the channel after trimming. (g) Y-shape structure fabricated at 4% NaAlg. (h) Y-shape structure fabricated at 5% NaAlg. Scale bar in (g) and (h) is 2 mm.