Underwater Fast Bubble Generating on Pitaya Thorn and Enhanced Biomimetic Gas Collection
writer：Lieshuang Zhong, Huan Chen, Lingmei Zhu, Lei Zhang, Shaomin Wang, Yongping Hou, and Yongmei Zheng*
keywords：bubble，gas collecting
source：期刊
Issue time：2022年
Underwater bubble is vital to various applications and many technologies are
applied for realizing efficient interfacial bubble generating. Here, the unique
underwater bubble generating by the thorn of pitaya is reported. Extensive
bubbles are generated underwater within few seconds on the thorn surface.
Microbumps and dual-scale ribs grow on the thorn surface, constructing the
unique dual-scale groove configuration along the thorn surface. Microbumps
equip groove with width gradient. The mechanism of how geometric con-
figuration of groove and surface wettability affect the bubble generating is
investigated. Bioinspired study shows that groove configuration can gen-
erate bubble within 2 ms by reassembling gas column within groove, which
lowers the energy barrier of bubble generating and accelerated gas molecular
diffusion toward bubble. Dual-scale groove is beneficial for strengthening
surface hydrophobicity and is favorable for reassembling. Besides, width
gradient induces the discrepancy of interface curvature along the groove and
further accelerates the bubble generating. Accordingly, the dual-scale gradient
groove can speed up bubble generating by ≈800%. Especially, the biomimetic
combinational groove can realize enhanced underwater gas collection. This
research reveals a new mechanism of fast bubble generating which is of great
potential for the applications based on underwater bubbles.