A Thermo-electromagnetically Actuated Microrobot for the Targeted Transport of Therapeutic Agents

Abstract

This work proposes the targeted transport of therapeutic agents using a thermo-electromagnetically actuated microrobot. This microrobot is fabricated via UV polymerization using 2D lithography and is composed of an electromagnetically actuated layer (polyethyleneglycol diacrylate dispersed with iron(II,III) oxide and a thermo-responsive layer (N-isopropylacrylamide). The microrobot can self-fold, driven by temperature changes, and can be steered using an electromagnetic actuation (EMA) system that provides external magnetic fields. In particular, during the EMA, pulling and rolling motions are applied to the unfolded and folded shapes, respectively, of the microrobot. As fundamental tests, the microrobot was characterized in terms of its magnetization curve, swelling properties, travel velocity, and shape changing behavior. In addition, typical polystyrene bead manipulations such as trapping, delivery, and release were performed using the microrobot. Finally, we performed an in vitro test for tumor therapy, in which the robot demonstrated the ability to trap, deliver, and release an anti-cancer drug (docetaxel) encapsulated in microbeads of approximately 300 mm in diameter with an appropriate drug concentration against a mouse mammary tumor cell line (4T1). The outcomes of this research suggest that our thermo-electromagnetically actuated microrobot is suitable for use in biomedical applications. © 2018 Institute of Control, Robotics and Systems and The Korean Institute of Electrical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature