Magnetic Programming of Soft-Bodied Wireless Minaiture Medical Robots

Wireless miniature medical robots have the unique capability of navigating, operating and staying inside risky and currently hard- or impossible-to-reach small spaces inside the human body. On the other hand, soft-bodied robots have the unique capabilities of shape programming, physical adaptation, safe physical interaction, and multifunctional diverse behaviors. Combining the strengths of both systems, this presentation reports on our recent soft-bodied wireless miniature medical robots with magneto-elastic active materials, actuated and controlled by external magnetic fields and gradients. Magnetizing hard magnetic microparticles, embedded inside the elastomeric body of soft robots, in programmed orientations and magnitudes enable diverse, dynamic and programmable shape deformations on these soft robots. We can even reprogram such magnetization properties to drastically change the shape modes of the robots. Using various magnetic (re)programming methodologies, first, we propose a magneto-elastic sheet-shaped soft robot, called Wormmate. Wormmate is inspired by soft-bodied organisms, such as spermatozoids, caterpillars, jellyfishes, and bacteria. It has over nine locomotion modalities at the same time to be able to navigate in diverse confined environments inside the human body. Next, a baby jellyfish-inspired magneto-elastic milliswimmer is shown to realize multiple functionalities by producing diverse controlled fluidic flows around its body. Then, an array of cilia-inspired magneto-elastic cilia is developed to generate metachronal waves for efficient biological fluid pumping and fluidic object manipulation. Moreover, we propose a jig-assisted 3D assembly method to create the most advanced soft miniature robots with heterogenous diverse materials and complex magnetic programming for medical device and other applications. Finally, it is possible to scale down such soft-bodied magnetic robots down to micronscale by merging two-photon 3D microprinting and magnetic assembly techniques. As example wireless soft medical devices, a soft peristaltic pump, a tubular surface-anchoring metamaterial-based shape-programmable soft device, a stent-like soft robot, and an on-demand drug-releasing soft capsule are demonstrated. Such soft devices are guided under ultrasound and x-ray imaging to achieve various local active medical functions, such as drug delivery, liquid biopsy, stem-cell treatment, embolization, clot opening, and hyperthermia.