Magnetic Microrobot Design and Control

Loading Physical Intelligence Department


  • Employ external magnetic fields for six-degrees-of-freedom         (6-DOF) microrobot control.


  • Investigate different imaging modalities as servoing method to localize and track the microrobot.


  • Implement autonomous strategies to position and orient microparticles in the workspace.

Project Members:

Joshua Giltinan

Xiaoguang Dong

Wenqi Hu

Past Members:

Chytra Pawashe

Steven Floyd

Guo Zhan Lum

Eric Diller

Zhou Ye

Selected Research Results and Papers

Six-Degrees-of-Freedom Remote Actuation of Magnetic Microrobots

Existing remotely-actuated microrobots powered by magnetic coils far from the workspace exhibit a maximum of only five-degrees-of-freedom (DOF) actuation, as a driving torque about the magnetization axis is not achievable. This lack of orientation control limits the effectiveness of existing microrobots for precision tasks of object manipulation and orientation for advanced medical, biological and micro-manufacturing applications. This paper presents a novel magnetic actuation method that allows these robots to achieve full six-DOF actuation by allowing for a non-uniform magnetization profile within the microrobot body. This non-uniform magnetization results in additional rigid-body torques to be induced from magnetic forces via a moment arm. A general analytical model presents the working principle for continuous and discrete magnetization profiles. Using this model, microrobot design guidelines are introduced which guarantee six-DOF actuation capability. Several discrete magnetization designs which possess reduced coupling between magnetic forces and induced rigid-body torques are also presented. A simple permanent-magnet decoupled prototype is fabricated and used to quantitatively demonstrate the accuracy of the analytical model in a constrained-DOF environment and qualitatively for free motion in a viscous liquid three-dimensional environment. Results show that desired forces and torques can be created with high precision and limited parasitic actuation, allowing for full six-DOF actuation using limited feedback control.

Eric Diller, Joshua Giltinan, Guo Zhan Lum, Zhou Ye, and Metin Sitti, “Six-Degrees-of-Freedom Remote Actuation of Magnetic Microrobots,” Robotics and Science Systems 2014. [Best Paper Award Finalist]

Selected Videos

Teleoperated star-shaped Mag-μBot

Mag-μBot in translation

A teleoperated star-shaped Mag-μBot inserting a peg into a gap

High-speed video of the side-view of a Mag-μBot in translation, displaying stick-slip motion, taken at 200 fps

List of Publications



Biomedical Applications of Untethered Mobile Milli/Micro-robots

M. Sitti, H. Ceylan, W. Hu, J. Giltinan, M. Turan, S. Yim, and E. Diller

Proceedings of the IEEE, in press.





Addressing of Micro-robot Teams and Non-contact Micro-manipulation

E Diller, Z Ye, J Giltinan, M Sitti

Small-Scale Robotics. From Nano-to-Millimeter-Sized Robotic Systems and Applications



Robotics: Three‐Dimensional Programmable Assembly by Untethered Magnetic Robotic Micro‐Grippers

E Diller, M Sitti

Advanced Functional Materials 24 (28), 4377-4377



Three-dimensional robotic manipulation and transport of micro-scale objects by a magnetically driven capillary micro-gripper

J Giltinan, E Diller, C Mayda, M Sitti

Robotics and Automation (ICRA), 2014 IEEE International Conference on, 2077-2082



SoftCubes: Stretchable and self-assembling three-dimensional soft modular matter

S Yim, M Sitti

The International Journal of Robotics Research, vol. 33 no. 8, 2014, pp. 1083-1097.





Two-dimensional magnetic micro-module reconfigurations based on inter-modular interactions

S Miyashita, E Diller, M Sitti

The International Journal of Robotics Research 32 (5), 591-613


Modular micro-robotic assembly through magnetic actuation and thermal bonding

E Diller, N Zhang, M Sitti

Journal of Micro-Bio Robotics 8 (3-4), 121-131



Independent control of multiple magnetic microrobots in three dimensions

E Diller, J Giltinan, M Sitti

The International Journal of Robotics Research 32 (5), 614-631




Two-dimensional autonomous microparticle manipulation strategies for magnetic microrobots in fluidic environments

C Pawashe, S Floyd, E Diller, M Sitti

Robotics, IEEE Transactions on 28 (2), 467-477



Control of multiple heterogeneous magnetic microrobots in two dimensions on nonspecialized surfaces

E Diller, S Floyd, C Pawashe, M Sitti

Robotics, IEEE Transactions on 28 (1), 172-182





Control methodologies for a heterogeneous group of untethered magnetic micro-robots

S Floyd, E Diller, C Pawashe, M Sitti

The International Journal of Robotics Research 30 (13), 1553-1565



Assembly and disassembly of magnetic mobile micro-robots towards deterministic 2-D reconfigurable micro-systems

E Diller, C Pawashe, S Floyd, M Sitti

The International Journal of Robotics Research, 0278364911416140



Control of multiple heterogeneous magnetic micro-robots on non-specialized surfaces

E Diller, S Floyd, C Pawashe, M Sitti

Robotics and Automation (ICRA), 2011 IEEE International Conference on, 115-120



Rotating magnetic micro-robots for versatile non-contact fluidic manipulation of micro-objects

E Diller, Z Ye, M Sitti

Intelligent Robots and Systems (IROS), 2011 IEEE/RSJ International ...





Two-dimensional contact and noncontact micromanipulation in liquid using an untethered mobile magnetic microrobot

S Floyd, C Pawashe, M Sitti

Robotics, IEEE Transactions on 25 (6), 1332-1342



Microparticle manipulation using multiple untethered magnetic micro-robots on an electrostatic surface

S Floyd, C Pawashe, M Sitti

Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International ...



Modeling and experimental characterization of an untethered magnetic micro-robot

C Pawashe, S Floyd, M Sitti

The International Journal of Robotics Research 28 (8), 1077-1094



Multiple magnetic microrobot control using electrostatic anchoring

C Pawashe, S Floyd, M Sitti

Applied Physics Letters 94 (16), 164108-164108-3





Dynamic modeling of stick slip motion in an untethered magnetic microrobot

C Pawashe, S Floyd, M Sitti

Proceedings of Robotics: Science and Systems IV, Zurich, Switzerland



An untethered magnetically actuated micro-robot capable of motion on arbitrary surfaces

S Floyd, C Pawashe, M Sitti

Robotics and Automation, 2008. ICRA 2008. IEEE International Conference on ...


Funding Agency

National Robotics Initiative