This Tiny Pangolin-Inspired Magnetic Medical Robot Is Hot Stuff — Quite Literally
Able to curl into a ball like its mammal inspiration, this robo-pangolin can heat up tissue and deliver targeted medicine on demand.
Researchers at the Max Planck Institute for Intelligent Systems, ETH Zürich, Tongji University, Koç University, and the Frontiers Science Center for Intelligent Autonomous Systems have designed a magnetic robot for medical heating applications — inspired by the scale-covered pangolin.
"Untethered magnetic miniature soft robots capable of accessing hard-to-reach regions can enable safe, disruptive, and minimally invasive medical procedures. However, the soft body limits the integration of non-magnetic external stimuli sources on the robot, thereby restricting the functionalities of such robots," the team explains of the problem it sought to solve. "One such functionality is localized heat generation, which requires solid metallic materials for increased efficiency. Yet, using these materials compromises the compliance and safety of using soft robots."
The solution, it turns out, was to take a leaf from nature's book, specifically focusing on the pangolin — the only mammal to have its body completely covered in hard scales, which overlap and move with the skin beneath. While the pangolin uses its coat of scales to curl into a protected ball in the face of danger, the team's pangolin-inspired bi-layer soft robot uses it to offer the best of both metallic and soft-body robotic approaches.
"We observed how pangolins in nature could still achieve flexible and unencumbered motion despite having keratin scales, which are orders of magnitudes harder and stiffer than the underlying tissue layers, simply by organising the keratin scales into an overlapping structure," the researchers explain. "Inspired by pangolins, an overlapping scaled design that allows users to concurrently realize on-demand thermal functionalities in tandem with shape-morphing and locomotion capabilities is introduced in this work."
The resulting robot can, like the pangolin, curl into a ball on demand — but it can also heat up its body, through exposure to a 338kHz radio-frequency field, allowing it to travel through the human body and deliver focused heat where it's required. In tests, the tiny prototype robot proved able to heat tissue up to 70°C (158°F) at distances over 5cm (around 2") in under 30 seconds. The same design also proved able to deliver a carried cargo — cleverly adhered to its body using beeswax, which could be melted using the heating system to drop it on demand.
The team's work has been published in the journal Nature Communications under open-access terms.
Main article image courtesy of the Max Planck Institute for Intelligent Systems.