Versatile magnetic hydrogel soft capsule microrobots for targeted delivery

Zichen Xu; Zehao Wu; Mingzhe Yuan; Yuanhe Chen; Wei Ge; Qingsong Xu

doi:10.1016/j.isci.2023.106727

Versatile magnetic hydrogel soft capsule microrobots for targeted delivery

iScience. 2023 Apr 25;26(5):106727. doi: 10.1016/j.isci.2023.106727. eCollection 2023 May 19.

Authors

Zichen Xu¹, Zehao Wu¹, Mingzhe Yuan², Yuanhe Chen¹, Wei Ge², Qingsong Xu¹

Affiliations

¹ Department of Electromechanical Engineering, Faculty of Science and Technology, University of Macau, Macau, China.
² Department of Biomedical Sciences and Centre of Reproduction, Development and Aging (CRDA), Faculty of Health Sciences, University of Macau, Macau, China.

Abstract

Maintaining the completeness of cargo and achieving on-demand cargo release during long navigations in complex environments of the internal human body is crucial. Herein, we report a novel design of magnetic hydrogel soft capsule microrobots, which can be physically disintegrated to release microrobot swarms and diverse cargoes with almost no loss. CaCl₂ solution and magnetic powders are utilized to produce suspension droplets, which are put into sodium alginate solution to generate magnetic hydrogel membranes for enclosing microrobot swarms and cargos. Low-density rotating magnetic fields drive the microrobots. Strong gradient magnetic fields break the mechanical structure of the hydrogel shell to implement on-demand release. Under the guidance of ultrasound imaging, the microrobot is remotely controlled in acidic or alkaline environments, similar to those in the human digestion system. The proposed capsule microrobots provide a promising solution for targeted cargo delivery in the internal human body.

Keywords: Biomedical materials; Magnetic property; Robotics.