Magnetic Fields Enhanced the Performance of Tubular Dichalcogenide Micromotors at Low Hydrogen Peroxide Levels

Abstract

Propulsion at the microscaleh as attracted significant research interest.I nt his work, an umerical simulation to explain the speed boost of up to 34 %e xperienced by transition metal dichalcogenides (TMD) basedm icromotors under the effecto fa pplied magnetic fields is described. The simulations showt hat, when an external magnetic field is applied, the flow regime changes from turbulentt ol aminar. This causes an increase in the residence time of the fuel over the catalyst surface, which enhances the oxygenp roduction. The more efficient generation and growth of the bubblesl ead to an increase of the capillary force exertedb y them.I nterestingly,t he effect is more pronounced as the level of fuel decrease. The validity of the modeli sa lso provenb yc omparingb oth theoretical and experimental results. Interestingly,t he speed enhancement in magnetic mode depends on geometrical factorso nly,a sasimilar phenomenonw as observed in av ariety of microjetsw ith av ariable surfacer oughness.T he understanding of such phenomena will open new avenues for understanding and controlling the motion behavior of high-towing-force catalytic micromotors.[a] V.

Near infrared-light responsive WS2microengines with high-performance electro- and photo-catalytic activities

“…The numerical simulations describing such phenomena have been very recently described by our research group. 43 From the above mentioned, it can be concluded that WS 2 does not inuence the peroxide decomposition activity. Yet, it can indirectly affect it by imparting an increased surface roughness to the inner Ni and Pt layers, as reected by the increased speeds.…”

Design and Control of the Micromotor Swarm Toward Smart Applications

“…Magnetic fields can also go through the barriers such as blood vessels or any other tissues easily. Different materials, such as Ni, [ 8,62 ] Fe 2 O 3 , [31b,63] Fe 3 O 4 , [ 64 ] Co, [ 65 ] FePt, [ 66 ] CoPt, [ 67 ] and CoFe 2 O 4 , [ 68 ] have been used for the integration of magnetic micromotors. Compared with the extraordinary progress on chemically propelled micromotors, relatively few applications have been described on magnetically propelled micromotors with tactic behavior.…”

“…The self‐propulsion of micro/nanomotors, along with the turbulent flows created by their motion, has not only improved the efficient micromixing and enhanced mass transfer but also endows such smart robots with targeted delivery functions. [ 6 ] Different energies, such as chemical fuels, [ 7 ] magnetic fields, [ 8 ] electromagnetic radiation, [ 9 ] and ultrasound, [ 10 ] have been used for efficient micromotor propulsion in complex biofluids. By integrating some specific recognition elements through surface modification, pathogens, [ 11 ] cancer cells [ 12 ] or toxic chemicals capture, [ 13 ] targets sensing, [ 14 ] and cancer cells/pathogens killing [ 15 ] can be achieved.…”

Recent Advances in Motion Control of Micro/Nanomotors

“…The difficulties in applying these artificial and biohybrid micro/nanomotors in pharmaceutical and biomedical industries lie in their nondurable propulsion and uncontrolled mobility, which not only makes the motor systems unstable but also extremely challenges their designed functionalities. Recently, increasing attention has been paid to unlock this critical bottleneck and various approaches to achieve motion and direction control of these motors have been reported, either by applying self-propelled motions or utilizing external fields such as light, [18][19][20][21] magnetic, [22][23][24] acoustic, [25] or electric field control. [26,27] The present review aims to summarize those most recently published studies and make in-depth discussion on the advantages and disadvantages of each approach, as well as DOI: 10.1002/aisy.202000049 Micro/nanomotors are able to convert energy in different forms into propulsion and movement with predesigned directions and velocities, enabling them to be self-propelled carriers and vehicles for the delivery of active pharmaceutical ingredients and other biomedical cargos to the target sites such as tumors.…”