A miniature robot inspired by the scaley skin of a pangolin has been developed by researchers at the Max Planck Institute for Intelligent Systems in Germany.
Soft robots have many advantages. The authors write: “Untethered magnetic miniature soft robots capable of accessing hard-to-reach regions can enable safe, disruptive, and minimally invasive medical procedures.” Magnetic-based locomotion is of particular interest in medical fields because magnetic fields can permeate human tissue safely.
But the soft body of these robots is also a limitation. Magnetic soft robots use magnetic energy at the expense of other types of energy. For example, heat energy is useful in many medical applications including coagulation and cutting. But it is an invasive procedure and difficult to localise its effect.
A method for controlling heat generation is by using solid metallic materials. But how do you create a robot that is both soft, and made of solid metal?
The team of researchers at the Max Planck Institute have answered this question by turning to the weird mammals, pangolins.
Pangolins are found in Asia and Africa. They are the only mammal to be covered in scales (though these scales are made of hardened hairs). It’s the overlapping pattern of these rigid scales that the scientists used to engineer their soft metallic robot.
The tiny robot is one centimetre wide and two centimetres long. It is only 0.2 mm thick. Emulating the overlapping pangolin scales, it is flexible, able to morph its shape and roll, but also heat up to 70°C.
Proof-of-concept experiments in the lab showed that the robot can perform medical treatments that may lead to future clinical applications. These include treating hyperthermia, cancer, or stopping bleeding in hard-to-reach areas such as in the stomach or intestines.
Such millirobots are also capable of demagnetising to release cargo, such as drugs, onto tissues.
Further testing is required before such tools are used for the delivery of therapeutic payloads or in heat-based treatments.