Pangolin-inspired robot capable of performing medical procedures in stomach

This millirobot (about 1 cm by 2 cm by 0.2 mm in size) has been created particularly for on-demand heating within the human body.

“The robot is actuated with a low-frequency magnetic field to the target location. Application of high-frequency magnetic field results in Joule heating of the metal plates. The heat energy can then be used to interact with the environment,” mentioned the study. 

Heat energy is commonly used in several medical treatments, such as devitalization and coagulation. As a result, it is one of the desirable features that untethered robots must have. 

There are several ways to achieve remote heating inside the human body, including thermochemical, acoustic, photothermal, and magnetic fields. 

“Magnetic actuation has emerged as a promising method for robots in biomedical applications due to the magnetic field’s ability to penetrate human tissues safely,” noted the study. 

Previously, engineers demonstrated using soft magnetic robots based on solid metals to undertake less intrusive medical procedures. They did, however, have minimal medical usefulness. As a result, the researchers developed this innovative robot, which can even deliver targeted drugs. 

Lab testing of the robot prototype 

This robot was tested in the laboratory by the team. The experiment demonstrated that the tiny robot could successfully heat up to 70°C and perform heating treatment on targeted tissues. 

In the future, the team wants to employ this robot in clinical applications for hyperthermia therapy, which involves heating a tissue to harm and kill cancer cells while having little influence on surrounding tissue. It can also be used to control bleeding in difficult-to-reach areas of the body. 

Furthermore, the robot also hones certain sophisticated features, such as delivering medication cargo or other therapeutic applications onto tissues. 

“The robots are capable of demagnetizing to release cargo onto the tissues, which could be used to deliver drugs in the future,” the authors mentioned in the research paper. 

Although further testing is needed, this technology has the potential to be a helpful clinical tool for the delivery of therapeutic payloads and heat treatment applications. 

The details about this soft robot prototype have been published in the journal Nature Communications. 

Study abstract:

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 localized 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. We show that the reported design achieves heating > 70 °C at large distances > 5 cm within a short period of time <30 s, allowing users to realize on-demand localized heating in tandem with shape-morphing capabilities. We demonstrate advanced robotic functionalities, such as selective cargo release, in situ demagnetization, hyperthermia, and mitigation of bleeding, on tissue phantoms and ex vivo tissues.