Supercapacitors in Motion: Autonomous Microswimmers for Natural‐Resource Recovery

Abstract

An electroadsorption technique similar to the ultrafast charging mechanism in supercapacitors is utilized to remove metals with different sizes and hydrophilicities from contaminated water using self-propelled microswimmers.T he swimmers carry graphite fibre or bismuth with alayered crystal structure providing high electrostatic double-layer capacitances.U nlike previous methods,t his electrochemical technique does not only utilizethe surface of the swimmers,but due to the interlayer spacing of the graphite and bismuth, it is able to store metals in % 400 layers,a llowing removal and recovery of > 50 ppm lithium in only 5min. Al arger interlayer distance between bismuth sheets allows the removal of bigger cations (sodium and calcium), expanding the application of this method to alarge variety of natural elements.Finally,magnetic navigation of charged swimmers to an oxygen-saturated media causes oxidation and thus immediate release of the metal ions from the swimmers.

Polyethylene‐Derived Activated Carbon Materials for Commercially Available Supercapacitor in an Organic Electrolyte System

“…Hence, supercapacitors have received considerable attention in fields requiring a high power density. [ 2–4 ] However, supercapacitors have a critical drawback that they have a relatively poorer energy density than secondary batteries. Consequently, improving the energy density of supercapacitors is one of the major missions to be accomplished.…”

Electric Field Induced Electrorotation of 2D Perovskite Microplates

“…However, it is still a significant challenge to precisely control the nanowire-based micromotors, because the viscous force dominates the motion with nonnegligible Brownian motion in the nanometer scale with a very low Reynolds number [ 29 , 30 ]. This reinforces the necessity of developing miniaturized components in the micrometer scale (>10 µm), which is required by, for instance, a microrobot with size of several hundred micrometers [ 31 , 32 ]. From this perspective, two-dimensional (2D) microplates can be regarded as ideal candidates in composing the miniaturized motors in micrometer scale.…”

Biomedical Micro‐/Nanomotors: From Overcoming Biological Barriers to In Vivo Imaging

“…These MNMs obtain sustaining energy from the fluid environment and exhibit self‐propelled motion. [ 12,13 ] Their motion mechanisms mainly include bubble propulsion, [ 14–18 ] self‐diffusiophoresis, [ 19–23 ] and self‐electrophoresis. [ 24–26 ] The other is powered by external field, such as magnetic field, [ 27–34 ] electric field, [ 35–38 ] ultrasonic field, [ 39–43 ] and light field.…”