Independent control of microrobots is a cardinal challenge for manipulation at micro/nano scale. In this paper, we design and assemble an electromagnetic setup to overcome some of the major obstacles in the independent control of microrobots. The demanding magnetic requirements are met by the presented experimental testbed that is able to produce magnetic fields and gradients of, respectively, 160 mT and 3.6 T/m at the center of the workspace. Through the design process of this testbed, we analyze the importance of design parameters and derive a quantitative analysis of the requirements for the dissipation of the generated heat. Further, we present and develop the model and software infrastructure, capable of running at 25 Hz, necessary for independent control of multiple microrobots. We also introduce two novel techniques for current-minimizing mapping of the desired forces into currents at the electromagnet. Finally, the capabilities of the setup are demonstrated through independent control of two, both identical and nonidentical, soft-magnetic microspheres in three-dimensional space—with average root mean square errors of 102$\mu$m and peak velocities of up to 331$\mu$m/s.

Untethered miniature robotics have recently shown promising results in several scenarios at the microscale, such as targeted drug delivery, microassembly, and biopsy procedures. However, the vast majority of these small-scale robots have very limited manipulation capabilities, and none of the steering systems currently available enables humans to intuitively and effectively control dexterous miniaturized robots in a remote environment. In this paper, we present an innovative micro-teleoperation system with haptic assistance for the intuitive steering and control of miniaturized self-folding soft magnetic grippers in 2-D space. The soft grippers can be wirelessly positioned using weak magnetic fields and opened/closed by changing their temperature. An image-guided algorithm tracks the position of the controlled miniaturized gripper in the remote environment. A haptic interface provides the human operator with compelling haptic sensations about the interaction between the gripper and the environment as well as enables the operator to intuitively control the target position and grasping configuration of the gripper. Finally, magnetic and thermal control systems regulate the position and grasping configuration of the gripper. The viability of the proposed approach is demonstrated through two experiments involving 26 human subjects. Providing haptic stimuli elicited statistically significant improvements in the performance of the considered navigation and micro-manipulation tasks.