A fast adaptive gating system based on the reconfigurable morphology of liquid metal via an electric field on porous surfaces

Abstract

Gallium-based liquid metal (LM) is one of the promising materials in design of microfluidic device and electrical components. Although much progress has been made, it is still challenging to achieve...

Critical Review on the Physical Properties of Gallium-Based Liquid Metals and Selected Pathways for Their Alteration

“…The oscillation of gallium-based liquid metals similar to that of mercury was already observed before (1999 by Mollencamp et al 134 ) and more recently by Yu et al 135 The more recent oscillating droplet was achieved by tilting the electrolyte container, resulting in cycles of electrochemical oxidation (low surface tension and deformation) and removal of oxide by the alkaline electrolyte (high surface tension). 135 The substantial reduction in interfacial tension upon application of positive potential (in NaOH electrolyte) enables jumping of droplets (upon reduction), 136 a transition between non-wetting (no potential) to wetting and pore infiltration, 137 and even penetration of porous materials, i.e., meshes, tissue paper, and sponges, with pore sizes down to 150 μm, albeit slower for smaller pore sizes, as shown in Figure 5f and g. 138 Notably, in this approach, wires can be drawn. Once the wires accumulate at the bottom of the setup, coalescence is observed.…”

Reactive wetting enabled anchoring of non-wettable iron oxide in liquid metal for miniature soft robot

“…Meanwhile, the phagocytosis effect 55 and the tensile force 56 of EGaIn eroded the coated Ag particles over time, exposing the Fe 3 O 4 @PDA surface to EGaIn, leading to the deterioration of wettability and the breaking of metastability. As a result, the dynamic phenomenon accompanied a morphological reconfiguration process of EGaIn droplet, which was obtained via wettability transition without external power, in contrast to the wetting-dewetting behavior of LM droplets stimulated by electric field 57 , 58 . More importantly, the wettability between iron oxide and EGaIn was significantly improved when Fe 3 O 4 nanoparticles were coated by enough Ag nanoparticles, paving the foundation of preparing magnetic LM composites.…”

Gradient monolayered porous membrane for liquid manipulation: from fabrication to application

“…A monolayered porous membrane is an efficient, stable and durable membrane material because of its good durability and difficult stratication, which plays an important role in selective liquid separation, water collection, unidirectional penetration and intelligent controllable wettability. 31,59,[78][79][80][81][82][83][84][85][86][87][88][89][90][91] 4.1 Unidirectional penetration Articial three-dimensional porous membranes with special wettability show directional transport behavior; that is, liquid can be transported from one surface of the membrane to the other, but the reverse transport is blocked. 18,85,92,93 Typically, unidirectional penetration membranes are composed of porous structures with an anisotropic surface structure and opposite wettability owing to the Laplace pressure of the bent liquid itself, which could drive the directional transport of the liquid through the porous structure.…”

“…A monolayered porous membrane is an efficient, stable and durable membrane material because of its good durability and difficult stratication, which plays an important role in selective liquid separation, water collection, unidirectional penetration and intelligent controllable wettability. 31,59,[78][79][80][81][82][83][84][85][86][87][88][89][90][91]…”