# Analysis and Comparison of Electromagnetic Microrobotic Platforms for Biomedical Applications
## 4 Conclusions  
We have provided a comprehensive review of the current advances of the biomedical microrobot in MIS and a comparison of various magnetic microrobotic systems developed by many researchers. One of the highest potential scientific and societal impact of the untethered microrobot would be the health-care and bio-engineering applications. As the robot size is decreased to the micro or nano-scale, previously inaccessible body locations would become available for high-resolution in situ and in vivo operations. Such remotely access will enable an extensive range of MIS operations. To this aim, the untethered microrobot would be wirelessly manipulated by the magnetic torque and force induced thanks to an EMA system. To precisely manipulate the biomedical microrobot, a key issue still relies on the suitable configuration of EMA platforms. Therefore, this work is devoted to present a general review of magnetic microrobots and magnetic microrobotic actuation setups. Especially, the choice of suitable magnetic microrobotic platform is a significant issue for the desired biomedical applications. The magnetic microrobotic systems with different configurations can produce respectively the magnetic field and gradient. As illustrated in Figure 1A, the magnetic field and gradient on the 2D surface generated by flat-arrangement magnetic microrobotic system are appropriate for the surface or skin operations. For the deeper surgical treatment, the magnetic microrobotic system can be utilized to control the medical microrobot to operate on members (e.g., arms, legs) for targeted therapy. This allows increasing the concentration of drugs in the part to be treated and reduces the impact on other parts of the body, that makes the treatment more effective and minimize side effects. Thus, the magnetic microrobotic system could be designed to surround the desired workspace as represented in Figure 1B since the applied part could be placed through the setup. Once again, with the requirements of a specific intraocular application, since the magnetic field with a safe intensity is arduous to launch deep into the body tissue providing enough magnetic field and gradient, the coils generating the magnetic field placed behind the head would be futile for the eye operation. Hence, the applied coils are all arranged around the eye in the front of the head. It is clear that the various magnetic microrobotic systems are utilized specifically for the pertinent biomedical applications in order to perform efficiently their functions. Methodology, R.C. ; Analysis, R.C. and D.F. ; Writing--original draft, R.C. and D.F. ; Writing--review and editing, R.C., D.F. and A.F. ; Project administration, A.F. ; Funding Acquisition, A.F. All authors have read and agreed to the published version of the manuscript. This work was supported by the French National Institute of Health and Medical Research (Inserm) \"Plan Cancer\" 2014-2019 program, Project: Microrobots Targeting Glioblastoma (MTG). \begin{table}
\begin{tabular}{l l l l} \hline
**EMA** & **Coils and Workspace** & **Advantages** & **Limitations** \\ \hline \multirow{6}{*}{8E [95]} & & Compact structure ; & \\  & & Arbitrary forces can be & Small volume with few \\  & & exerted on each & accessibility; Weak \\  & & microrobot & magnetic field \\  & & independently and & and gradients. \\  & & simultaneously. & \\ \hline \multirow{3}{*}{[59, 60]} & & Good magnetic field; & \\  & & Hemispherical coils & Complex magnetic \\  & & arrangement. & field description. \\ \hline \multirow{3}{*}{9E [96]} & & Independent 3D control & Advanced control \\  & & of pairs of microrobots; 6 & strategies are required; \\ \cline{1-1}  & & DOFs motion; Workspace & Large amount of energy \\ \cline{1-1}  & & accessibility. & consumption \\ \cline{1-1} \cline{2-4}  & & & and heating. \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
**Institutional Review Board Statement:** Not applicable.