Multi-Legged Magnetic Soft Robot for On-Demand Targeted Delivery in Pulmonary Environments

Intrabronchial drug delivery is an important method for treating respiratory diseases. Precise and selective deep-lung delivery of drugs is still challenging through inhalation administration and bronchoscopes, due to the passive transport and insufficient maneuverability in narrow and tortuous distal airways. Herein, a magnetic-driven soft robot with a multi-legged structure is developed for minimally invasive and precise targeted drug delivery in the lung. The robot exhibits multimodal and adaptive locomotion in complex airways, relying on its soft nature. A magnetothermal-triggered and on-demand liquid drug release mechanism is integrated onto the robot. Rolling, stick-slip and crawling motion modes can be achieved, and the mode transition is realized to enhance the adaptivity. Precise navigation in complex environments and the distal bronchial tree of a phantom is realized. The magnetothermal-induced drug release is also demonstrated. Ex vivo distal navigation, targeted drug delivery and retrieval of the robot in a porcine lung are validated.