Design and Motion Controllability of Emerging Hydrogel Micro/Nanorobots

Micro/nanorobots (MNRs) are promising for biomedical applications due to their unconstrained nature and small enough size to pass through many tiny environments. However, the efficient movement of MNRs in liquid environments is still a challenge due to the low Reynolds number environment and the Brownian motion of particles. Herein, emerging MNRs with hydrogel-loaded magnetic particles are designed. The proposed hydrogel MNRs (HMNRs) exhibit biocompatible and controllable characteristics. The motion controllability of HMNRs is realized by applying oscillating magnetic field and customized magnetic field. Experimentally, it is demonstrated that the HMNR swarms driven by the oscillating magnetic field exhibit a faster motion speed than the MNR swarms composed of magnetic particles. The HMNRs show precise controllability of the movement in the complex pipeline under the control of customized magnetic field. This method can offer a more benign approach to the general production of HMNRs for biological applications.