Fuel-free locomotion of Janus motors: magnetically induced thermophoresis

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

We present fuel-free locomotion of magnetic spherical Janus motors driven by magnetically induced thermophoresis--a self-diffusive propulsion of an object in any liquid media due to a local temperature gradient. Within this approach an ac magnetic field is applied to induce thermophoretic motion of the objects via heating a magnetic cap of the particles, while an additional dc magnetic field is used to orient Janus motors and guide their motion on a long time scale. Full control over the motion is achieved due to specific properties of ultrathin 100-nm-thick Permalloy (Py, Fe₁₉Ni₈₁ alloys) magnetic films resulting in a topologically stable magnetic vortex state in the cap structure of Janus motors. Realized here magnetically induced thermophoretic locomotion does not require catalytic chemical reactions that imply toxic reagents. In this respect, we addressed and successfully solved one of the main shortcomings in the field of artificial motors, namely being fully controlled and remain biocompatible. Therefore, our approach is attractive for biotechnological in vitro assays and even in vivo operations, since the functioning of Janus motors offers low toxicity; it is not dependent on the presence of the fuel molecules in solution. Furthermore, the suggested magnetic ac excitation is superior compared to the previously proposed optically induced heating using lasers as it does not require transparent packaging.

Details

Original languageEnglish
Pages (from-to)1360–1367
Number of pages8
JournalACS Nano
Volume7
Issue number2
Publication statusPublished - 26 Feb 2013
Peer-reviewedYes

External IDs

PubMed 23268780
Scopus 84874430303

Keywords

Keywords

  • Glass/chemistry, Magnetic Fields, Motion, Silicon Dioxide/chemistry, Temperature, Water/chemistry