Bio-Inspired Elastic Liquid-Infused Material for On-Demand Underwater Manipulation of Air Bubbles

Abstract

Precise and robust manipulation of air bubbles will favor intense demands from governing processes of chemical reactions to enhancing transportation efficiency in multiphase engineering systems. Inspired by the working mechanism of mucous lining in lung alveoli, the elastic liquid-infused material (eLIM) is constructed by infiltrating an interconnected porous elastomer with a low-surface-energy lining liquid. With the help of the lining liquid, the pore pressure of the interconnected channels in eLIM can be reversibly regulated under mechanical stretching, balancing the capillary pressure in the channels with diverse radii and allowing gas flow in these channels. Therefore, air bubbles could be transported in and across the eLIM, showing on-demand control on the bubble contact angle, merging and splitting in an active and precise manner. The robust manipulation strategies on air bubbles can find applications in bioreactors and many other bubble-involved processes.

A Multi‐Bioinspired Dual‐Gradient Electrode for Microbubble Manipulation toward Controllable Water Splitting

“…Bubble manipulation using an open surface promotes its superiority in mass/energy exchange as it benefits a direct and sufficient interaction between gas and the aqueous solution. [ 4 ] Thus, a number of research groups were devoted to designing specific surfaces with specific controllability of bubbles, e.g., superhydrophobic cone, [ 5 ] superaerophilic geometry‐gradient channel, [ 6 ] lubricant‐infused slippery surface, [ 7 ] elastic liquid‐infused material, [ 8 ] Janus mesh, [ 9 ] etc. Previous studies, to some extent, have realized spontaneous and directional bubble transport underwater, including 1D bubble transport along channels with the assistance of wettability gradient derived from a Janus interconnected structure, [ 9,10 ] 2D transport depending on specific inclined planes with the aid of buoyancy or on specific asymmetric surfaces with geometric gradient, [ 11 ] demonstrating meaningful but limited bubble transport processes.…”

Progress in bio-inspired porous membranes

“…(c) Bio-inspired porous membrane system of a molecule-filtrating glomerulus inspired by the glomerulus and natural sponge [8] . (d) Illustration for the fabrication procedure of bio-inspired PVA/PAN composite porous membrane for hemodialysis [24,54,56] . 例如, 本课题 组 [53] 采用激光刻蚀技术制备了弹性有机高分子多孔 膜, 再将功能液注入到该膜的孔道中, 获得一种在恒压 自动打开, 进行物质交换(图5(a)) [58] .…”

“…(c) Dynamic gas and liquid transport process of liquid gating elastomeric porous membrane [53] . (d) Cross section and on-demand bubble manipulation process of bio-inspired elastic liquid-infused membrane [54] 2021 年 4 月 第 66 卷 第 10 期 信使分子NO通过膜孔时, 与膜孔内的铁卟啉结合时, 促使膜的孔道打开, 钾离子能快速通过膜的孔道. 当停 止NO刺激改为太阳光照射时, NO从亚硝酰基铁卟啉 中解离, 膜孔道重新关闭, 此时钾离子不能穿过膜孔.…”

Electrically Induced Underwater Superaerophilicity/Superaerophobicity Switching on Polypyrrole‐Coated Mesh Films for Selective Bubble Permeation

“…[20] In addition to water and oil, studies about responsive wetting performances of gas bubble in water have also aroused much attention. [21] Recently, Wu et al realized in situ regulation from superaerophilicity to superaerophobicity on titanium surfaces by controlling solution surface tension through adding a certain amount of alcohol to the water; [22] Zhang et al reported a liquid-infused porous elastomer, on which the bubble wettability can be reversibly controlled through regulating the mechanical stretching; [23] Jiao et al fabricated TiO 2 square micropillar arrays on titanium sheets and displayed switchable bubble wettability by alternately heating in a dark environment and ultraviolet irradiation in alcohol; [24] Jiang et al presented a multilevel polymeric substrate that can turn from aerophilicity to aerophobicity under heating. [25] In addition, through alternately prewetting and drying treatment was also exhibited on some other surfaces to switch bubble wettability, such as copper mesh, [26] alloy, [27] titanium, [28] stainless, [29] etc.…”