The pangolin's ability to curl up their scale-covered bodies in a flash was the inspiration behind the robots, designed by the Physical Intelligence Department at the Max Planck Institute for Intelligent Systems in Stuttgart.
Pangolins are the only species of mammal completely covered with hard scales made of keratin. The scales overlap and are directly connected to the underlying soft skin layer, allowing the animals to curl up into a ball in case of danger.
Inspired by this skill, the researchers developed a flexible robot made of soft and hard components that can become a sphere in the blink of an eye, with the additional feature that the robot can emit heat when needed, for use in future medical procedures.
Pangolin-inspired robots / Max Planck Institute for Intelligent Systems Tübingen
Image credit: Max Planck Institute for Intelligent Systems Tübingen
The robot design is no more than two centimetres long and consists of two layers: a soft layer made of a polymer studded with small magnetic particles and a hard component made of metal elements arranged in overlapping layers.
When the robot is exposed to a low-frequency magnetic field, the researchers can roll it up and move it back and forth as they wish. The metal elements stick out like the animal's scales, without hurting any surrounding tissue.
Once it is rolled up, the robot could transport particles such as medicines. The vision is that such a small machine will one day travel through our digestive systems, for example.
Conceptual illustration of the pangolin-inspired robot operating in the small intestine. / Max Planck Institute for Intelligent Systems Tübingen
Image credit: Max Planck Institute for Intelligent Systems Tübingen
The pangolin-inspired robot would also make use of thermal energy for medical applications.
Thermal energy is used in several medical procedures, such as treating thrombosis, stopping bleeding and removing tumour tissue. However, untethered robots that can move freely and emit heat at the same time are rare.
In contrast, the pangolin robot is able to heat up to over 70°C when exposed to a high-frequency magnetic field, thanks to the built-in metal.
This ability to reach higher temperatures, combined with its small size and high flexibility, could allow the robot to reach even the narrowest and most sensitive regions in the body in a minimally invasive and gentle way.
The robot design was described in a research paper published in Nature Communications.
