Chemical reaction dependency, magnetic field and surfactant effects on the propulsion of disk‐like micromotor and its application for E. coli transportation

Abstract

In this article, a miniature micromotor comprising of gold, nickel, and platinum is proposed. Herein, platinum acting as a chemical catalyst stimulates hydrogen peroxide to decompose into water and oxygen bubbles separated from the surface, which conversely produces a recoil force to drive the gold-nickelplatinum micromotor propelling forward. The micromotor is synthesized by a layer-by-layer coating strategy based on the micro-electro-mechanical systems technology. The propulsion of the as-synthesized micromotor is experimentally conducted in diluted hydrogen peroxide both with and without the presence of external magnetic field, disclosing that oxygen bubbles are produced and separated from the platinum surface. Moreover, the results show that the speed of the gold-nickel-platinum micromotor is larger at higher hydrogen peroxide concentration, and the micromotor is able to move forward in an either linear or circular trajectory depending on the separation site of oxygen bubbles, the propulsion path of the micromotor can be manipulated by external magnetic field as well. Hence, the propulsion of the micromotor is chemical reaction-and magnetic field-dependent. In addition, the surfactant effect on the propulsion of micromotor and its application for E. coli transportation are investigated.

Strategies in design of self-propelling hybrid micro/nanobots for bioengineering applications

“…So, irrespective of the different shapes/sizes, a micro/nanomotor will follow the same bubble propulsion mechanism when hydrogen peroxide has used as fuel for locomotion. Furthermore, the concentration of hydrogen peroxide is directly proportional to the speed of the gold (Au)-nickel (Ni)-platinum (Pt) micro/nanobots [33][34][35][36]. The bursting of oxygen bubbles powers micro/nanobots that can freely be driven in a circular motion in hydrogen peroxide solution [35,36].…”

Five in One: Multi‐Engine Highly Integrated Microrobot

“…[ 4 ] For example, nanorods driven by self‐electrophoresis [ 2 ] and micro‐disks driven by bubbles flow. [ 5 ] In addition, the motion of the micro/nanorobots can be driven by external physical fields. [ 6 ] Such as these classic examples: nano‐spirals driven by magnetic fields, [ 7 ] micro‐bowls driven by acoustic fields, [ 8 ] nanorods driven by electric fields, [ 9 ] and microspheres driven by optical fields.…”

“…[ 19 ] In recent years, the introduction of magnetic materials has preliminarily achieved directional control of micro/nano robots under other driving mechanisms. [ 5 ] An additional hurdle is that the existing drive system often has limitations, such as the 3D magnetic field coil required by the magnetic drive system and the energy conversion device required by the ultrasonic drive system. [ 12 ] These devices may not meet the requirements under actual conditions.…”

Vector-Controlled Wheel-Like Magnetic Swarms With Multimodal Locomotion and Reconfigurable Capabilities

“…One of the recent frontiers of micro-/nanorobots researches involves swarms that stem from bacteria colonies ( Felfoul et al, 2016 ), bird flocks ( Colorado and Rodewald, 2015 ) and insect swarms ( Gelblum et al, 2015 ) in nature, exhibit high environmental adaptability and enhanced tasking capabilities for environmental remediation ( Joh and Fan, 2021 ; Liu et al, 2020a ; Liu et al, 2020b ), micromanipulation ( Xu et al, 2020 ; Kagan et al, 2011 ; Solovev et al, 2010 ) and biomedicine ( Servant et al, 2015 ; Melde et al, 2016 ). Swarming micro-/nanorobots could be energized by different external stimuli, such as magnetic fields ( Yu et al, 2018a ; Li et al, 2015 ), chemicals ( Hu et al, 2020 ; Chang et al, 2019 ), electric fields ( Yan et al, 2016 ; Bricard et al, 2015 ), light ( Dong et al, 2018 ; Ibele et al, 2009 ), and ultrasound ( Xu et al, 2019 ; Xu et al, 2015 ). Inspired by the behavior of natural swarms, various dynamic patterns, such as liquid ( Xie et al, 2019 ), chain ( Martinez-Pedrero et al, 2015 ), ribbon ( Yu et al, 2018b ), vortex ( Yu et al, 2018a ; Kokot and Snezkho, 2018 ), and ellipse ( Yu J. et al, 2021 ; Zhang et al, 2021 ), have been reproduced by artificial swarming strategies.…”