Wireless Light-Emitting Electrochemical Rotors

Abstract

Bipolar electrochemistry has been shown to enable and control various kinds of propulsion of nonwired conducting objects: translation, rotation, and levitation. There is a very rapid development in the field of controlled motion combined with other functionalities. Here we integrate two different concepts in one system to generate wireless electrochemical motion of a specifically designed rotor and track its polarization simultaneously by electrochemical light emission. Locally produced hydrogen bubbles at the cathodic pole of the bipolar rotor are the driving force of the motion, whereas [Ru(bpy)]Cl and tripropylamine react at the anodic extremity, thus generating an electrochemiluminescence signal with an intensity directly correlated with the orientation of the rotor arms. This allows in a straightforward way the qualitative visualization of the changing interfacial potential differences during rotation and shows for the first time that light emission can be coupled to autonomously rotating bipolar electrodes.

Electrochemistry‐Based Light‐Emitting Mobile Systems

“…Although this type of motion could be simply achieved by connecting an electric conductor to an external motor, [102] wireless propulsion is an additional desirable feature. For example, a homemade four‐blade rotor exposed to an electric field, in the presence of Ru(bpy) 3 2+ and TPrA, [103] was propelled by the continuous accumulation/release process of H 2 bubbles formed at the cathodic pole, whereas ECL emission occurs at the anodic pole. An almost linear dependence of the rotation speed as a function of applied potential was obtained.…”

Advances in bipolar electrochemiluminescence for the detection of biorelevant molecular targets

“…The trick was to select a glucose dehydrogenase because the β-nicotinamide adenine dinucleotide (NADH) enzymatic co-product acts also as an ECL sacrificial co-reactant, enabling thus a substrate-dependent ECL signal. Apart from these systems, the influence of the orientation of a bipolar electrode mounted on a rotor was also investigated to demonstrate the feasibility of alternating ECL controlled by the rotation speed [39,40].…”

Geometry Design, Principles and Assembly of Micromotors

“…Moreover, the action of charge separation using external fields is interesting for catalytic nano-/microparticles, where, for example, a catalytic powder can be suspended in aqueous solution for reaction, without physical connections to the surface of electrode. Several groups showed motion of conventional semiconductor diodes and pumps in external AC fields [ 206 ], electrochemical rotors [ 207 ], nanowire diodes [ 208 ], trajectory influenced by AC electrokinetics [ 209 ], characterized motion by particle–electrode impact voltammetry [ 210 ], and motion of liquid metal Al–Ga–In motors moving at high speed up to 43 cm·s −1 under 20 V voltage [ 211 ].…”