Self-assembly of robotic micro- and nanoswimmers using magnetic nanoparticles

Research Paper

DOI: 10.1007/s11051-014-2737-z

Cite this article as:
Cheang, U.K. & Kim, M.J. J Nanopart Res (2015) 17: 145. doi:10.1007/s11051-014-2737-z
Part of the following topical collections:
  1. Nanotechnology in Biorobotic Systems

Abstract

Micro- and nanoscale robotic swimmers are very promising to significantly enhance the performance of particulate drug delivery by providing high accuracy at extremely small scales. Here, we introduce micro- and nanoswimmers fabricated using self-assembly of nanoparticles and control via magnetic fields. Nanoparticles self-align into parallel chains under magnetization. The swimmers exhibit flexibility under a rotating magnetic field resulting in chiral structures upon deformation, thereby having the prerequisite for non-reciprocal motion to move about at low Reynolds number. The swimmers are actuated wirelessly using an external rotating magnetic field supplied by approximate Helmholtz coils. By controlling the concentration of the suspended magnetic nanoparticles, the swimmers can be modulated into different sizes. Nanoscale swimmers are largely influenced by Brownian motion, as observed from their jerky trajectories. The microswimmers, which are roughly three times larger, are less vulnerable to the effects from Brownian motion. In this paper, we demonstrate responsive directional control of micro- and nanoswimmers and compare their respective diffusivities and trajectories to characterize the implications of Brownian disturbance on the motions of small and large swimmers. We then performed a simulation using a kinematic model for the magnetic swimmers including the stochastic nature of Brownian motion.

Keywords

Micro- and nanorobotics Micro- and nanoswimmers Low Reynolds number Magnetic self-assembly Magnetic nanoparticles 

Supplementary material

11051_2014_2737_MOESM1_ESM.mpg (88.4 mb)
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Supplementary material 2 (MPG 63,864 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2015

Authors and Affiliations

  1. 1.Department of Mechanical Engineering & MechanicsDrexel UniversityPhiladelphiaUSA