Liquid Jetting‐Based Miniature Robotic Navigation in Confined Fluidic Spaces

Miniature robots offer great potential for accessing hard‐to‐reach areas often encountered in physiological and natural environments. However, current miniature robots lack a unified design, fabrication process, and actuation mechanism across the mm‐to‐cm scale to enable competitive locomotion, such as fast movement and spatial maneuvers in liquids. To address this, we introduce a new class of miniature robots, JetBots, equipped with a carefully designed liquid‐jetting‐based mechanism. Measuring from 1.8 mm to 0.8 cm, the JetBots can perform fast locomotion, spatial maneuvering, and various functions. A 1.8 mm JetBot can reach a propulsion speed of 30.3 cm/s in static water. Using rapid momentum transfer, we demonstrate that a 2.7 mm JetBot can quickly steer with 648.8°/s in static water, navigate bifurcations, traverse complex tortuous luminal paths, and puncture soft materials to deliver and sample. Extending the liquid jetting mechanism to the cm scale, we show that a 0.8 cm JetBot can achieve speeds up to 11.8 cm/s, rapid steering with 262°/s, and controlled movement in confined underwater environments. The JetBots highlight that integrating the liquid‐jetting mechanism can notably enhance the locomotion and functionality of miniature robots for various applications in confined fluidic environments, such as environmental, agricultural, and medical settings.