Design, fabrication and application of magnetically actuated micro/nanorobots: a review

Abstract

Magnetically actuated micro/nanorobots are typical micro- and nanoscale artificial devices with favorable attributes of quick response, remote and contactless control, harmless human-machine interaction and high economic efficiency. Under external magnetic actuation strategies, they are capable of achieving elaborate manipulation and navigation in extreme biomedical environments. This review focuses on state-of-the-art progresses in design strategies, fabrication techniques and applications of magnetically actuated micro/nanorobots. Firstly, recent advances of various robot designs, including helical robots, surface walkers, ciliary robots, scaffold robots and biohybrid robots, are discussed separately. Secondly, the main progresses of common fabrication techniques are respectively introduced, and application achievements on these robots in targeted drug delivery, minimally invasive surgery and cell manipulation are also presented. Finally, a short summary is made, and the current challenges and future work for magnetically actuated micro/nanorobots are discussed.

Medical micro- and nanomotors in the body

“…Magnetic field has been widely used for MNMs propulsion because of its noninvasiveness and superior controllability 96 . Generally, magnetic components need to be incorporated into the motor system to achieve magnetic responsiveness under the magnetic field ( Fig.…”

Micro-/nanoscale robotics for chemical and biological sensing

“…The direction of this motion (in terms of forward versus backward) can be changed by simply reversing the direction of rotation of the applied magnetic field. 28,31 Similar in principle to how corkscrew motion is achieved, surface-assisted motion gets its name from the use of a physical boundary to break spatial symmetry for the purpose of generating a walking or rolling motion of micro-/ nanorobots at low Reynolds numbers. 31 These micro-/ nanorobots are commonly called "surface walkers" or "surface rollers" and can take on a variety of shapes including nanorods and microtubes as well as Janus particles (Fig.…”

Magneto-Mechanical Approach in Biomedicine: Benefits, Challenges, and Future Perspectives

“…Basically, three types of applied MFs can be distinguished in magneto-mechanical actuation: alternating magnetic field (AMF, Figure 1 a), rotating magnetic field (RMF, Figure 1 (b1,b2), and static gradient magnetic field (SMF, Figure 1 c). In addition, the combination of RMF with SMF is used to create micro- or nanorobots with drilling motion ( Figure 1 d) [ 12 ]. In each type of external MF, the MNP magnetic moment vector will tend to align with the MF vector , and the mechanics of this process will depend on many different parameters, which will be discussed in this section.…”