Magnetic and injectable Fe-doped liquid metals for controlled movement and photothermal/electromagnetic therapy.

As a multifunctional material, gallium-based liquid metal (LM) mixtures with metal particles dispersed in the LM environment display many excellent and intriguing properties. In this study, biomaterials were prepared by mixing Fe particles with LM for easily manageable photothermal or electromagnetic therapy and evaluated. Clinically, the fabricated 5%Fe/LM sample was injectable and radiopaque, which allowed its smooth delivery through a syringe to the target tissues, where it could help achieve clear imaging under CT. Meanwhile, because of the loading of Fe particles, the 5%Fe/LM possessed a magnetic property, implying a high manipulation capability. According to the experiments, the capsule containing 5%Fe/LM when placed in an isolated pig large intestine could move as desired to the designated position through an external magnet. Further, the biosafety and low toxicity of the 5%Fe/LM were confirmed by cytotoxicity tests in vitro, and the temperature changes at the interface between the 5%Fe/LM and intestinal tissue after near-infrared (NIR) laser irradiation were determined through theoretical modeling and numerical simulation data analysis. Due to the excellent photothermal and magnetothermal effects of LM, the temperature of the 5%Fe/LM injected into the rabbit abdominal cavity could significantly increase under NIR laser or alternating magnetic field (AMF) administration. As a novel functional biomaterial, the 5%Fe/LM exhibited promising potential for designated position movement and photothermal or magnetothermal therapy in the near future.

LM-Jelly: Liquid Metal Enabled Biomimetic Robotic Jellyfish.

Jellyfish have attracted worldwide attention owing to their fantastic moving styles, which also inspired development in soft robotics to meet the demands of underwater surveillance. In this study, a soft robotic jellyfish integrated liquid metal coil, and magnetic field is proposed for the first time to mimic the soft rowing propulsion of oblate jellyfish. The soft robotic jellyfish is actuated by the entirely soft electromagnetic actuators that enabled the gentle motion. Through conceptual experiments and computational fluid dynamics simulations, we systematically interpreted the mechanism of this robotic jellyfish and various factors to dominate its movement behaviors, which involve vortex formation and ascending modalities. Besides, underwater monitoring and bio-friendliness of robotic jellyfish were also demonstrated to illustrate its potential application scenarios and gentle motion characteristics. This study will help to broaden the vistas for liquid metal enabled bionic robotics in a wide range of underwater applications.