Inclination‐Enabled Generalized Microfluid Rectifiers via Anisotropic Slippery Hollow Tracks

Abstract

The power of spontaneous maneuvering of microfluids that allow gas or liquid to penetrate along a single direction, is usually endowed with the wettability gradient and the Laplace pressure difference through tailoring special solid‒gas interfacial geographies. Herein, inspired by the structures on rice leaves and the slippery surfaces of the pitcher plant, anisotropic slippery hollow tracks (ASHTs) are fabricated and thus propose a class of unique inclination‐enabled bubble “diode”, on which one‐way bubble penetration can be reversibly switched on/off. The minimum transition tilt angle is subject to the tract spacing and the infused oil amount. The underlying mechanism of bubble penetration is attributed to the competition between the variable buoyancy component and the interfacial energy gradient perpendicular to the samples. A wide spectrum of generalized microfluid maneuvering capabilities is further demonstrated, including heavy oil selective penetration, underwater CO2 gas collection, and even dry/wet environment management in smart buildings, which are challenging for conventional counterparts. This framework should facilitate the development of microfluid control with favorable retainability and wide applicability in multiple fluids.

Recent advances in functional micro/nanomaterials for removal of crude oil via thermal effects

“…Recently, new adsorbents with hydrophobicity and oleophilic properties have been favoured over other treatment methods because they meet the above conditions. 38–41 Adsorbents are applied easily, are reusable, low cost and non-toxic to marine life and the environment. 42–45 However, due to the fact that 40% of the world's oil reserve is heavy crude oil, its high viscosity (10 3 to 10 5 mPa s at room temperature) strongly inhibits crude oil adsorption that relies on van der Waals forces and capillary action.…”

On-Demand Transport Bubbles Adhering to Noncontiguous Patterned Superhydrophobic Surfaces Using a Superhydrophobic Tweezer

“…Most techniques for manipulating underwater bubbles primarily focus on altering the shape of the solid surface, such as planes, − wires, , or cones, − as well as adjusting the surface’s wettability. − These particular solid surfaces create conditions of either attraction or constraint on bubbles, which are then subject to various driving forces to achieve directional bubble transport. These forces can be broadly categorized into three main groups: buoyancy, ,, Laplace pressure, ,− and external force. , The buoyancy driving force in the first category can be easily controlled by altering the inclined angle of the substrate . Moreover, the effective length of the three-phase contact line is the determining factor in bubble manipulation .…”

“…17−19 These particular solid surfaces create conditions of either attraction or constraint on bubbles, which are then subject to various driving forces to achieve directional bubble transport. These forces can be broadly categorized into three main groups: buoyancy, 9,20,21 Laplace pressure, 8,12−16 and external force. 10,11 The buoyancy driving force in the first category can be easily controlled by altering the inclined angle of the substrate.…”

Magnetohydrodynamics and viscosity variation in couple stress squeeze film lubrication between rough flat and curved circular plates

“…Bai et al 44 examined the thermo-mechanical mechanism subject to soil particle re-arrangement of thermodynamics granular. Bian et al 45 , Zhu et al 46 and Zhang et al 47 respectively worked bioinspired magnetism-responsive hybrid microstructures, generalized micro-fluid rectifiers via anisotropic slippery hollow tracks and nonlinear hysteretic behaviours with strain-stiffening of magnetorheological gel composite applications. Attributes of cavity dynamics, trajectories and forces on vertical water entries, shear thickening fluids and behaviour between fluid and structure from coupling system respectively investigated by Lyu et al 48 , Sun et al 49 and Huang et al 50 .…”