Hybrid Hydrogel‐Magnet Actuators with pH‐Responsive Hydrogels for Gastrointestinal Microrobots

In article number 2301060, Eric Diller and co-workers demonstrate a hybrid hydrogel-magnet actuator that comprises a pH-responsive hydrogel placed in between two attracting magnets in a tube. The actuator is shown to drive two translational magnetic mechanisms via magnetic repulsive forces in the gastrointestinal tract. In the stomach, the mechanisms remain untriggered. In the small intestines, the pH-responsive hydrogel in the actuator will swell to a critical hydrogel height. At the critical hydrogel height, the translational magnetic mechanisms are triggered in the small intestines and can be used in applications such as drug delivery.