Researchers and engineers frequently look to the natural world for inspiration when designing robots. Over the years, a wide variety of wildlife, from birds and bats to snakes and jellyfish, served as muses for ambitious designers as they strove to build better, stronger, and faster robots. Recently, researchers have turned to the pangolin with its unique overlapping scales as a model for the latest technical innovation.

But first, what is a pangolin? This peculiar mammal is covered in keratin scales that are directly connected to the skin below and are designed to protect it from predators. If a pangolin feels threatened, it will cover its head with its scale-covered legs. If attacked, the pangolin, like an armadillo, can curl into a tight ball, using its scales as articulating armor. Scientists from the Physical Intelligence Department at Max Planck Institute for Intelligent Systems in Stuttgart, Germany, used the pangolin’s evolutionary gift as the inspiration for their magnetically controlled soft medical robot.

Lead by Prof. Dr. Metin Sitti, the team’s resulting paper, titled "Pangolin-inspired untethered magnetic robot for on-demand biomedical heating applications," was published in Nature Communications earlier this year. In an excerpt from the paper’s abstract, researchers wrote: “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. One such functionality is localised heat generation, which requires solid metallic materials for increased efficiency. Yet, using these materials compromises the compliance and safety of using soft robots. To overcome these competing requirements, we propose a pangolin-inspired bi-layered soft robot design.”

According to the team, the robot, which measured 2 cm in length, is composed of two layers. The first is a soft layer consisting of polymer studded with small magnetic particles. The second hard layer is made of metal elements arranged in overlapping layers. A low-frequency magnetic field causes the robot to roll up, allowing researchers to move the technological wonder as they wish. Since the metal scales are designed to not hurt human tissue, the robot has the ability to travel through the body, transporting particles and medicines as needed. In addition, the robot can heat up to over 70oC, allowing it to treat various medical conditions like thrombosis, stopping bleeding, and removing tumor tissue.