Folding micro-robot as a replacement for endoscopy

Researchers have created a folding robot that requires no batteries and can still perform complex movements controlled via a wireless magnetic field.

A research team from Harvard University applied the principle of the Japanese art of origami that turns a simple paper into complex, three-dimensional shapes. The co-author of the study Je-sung Koh explained, “Like origami, one of the main points of our design is simplicity. This system requires only basic, passive electronic components on the robot to deliver an electric current -- the structure of the robot itself takes care of the rest.”

The robots are thin and flat – similar to the origami paper – plastic tetrahedrons with three outer triangles that are attached to central triangle by hinges and tiny circuit on the central triangle; similar to the origami paper.

Coils made of a metal type known as shape-memory alloy (SMA) are connected to the hinges that would turn the robot back to its original shape after being twisted by being heated to a certain temperature. When the hinges are flat the coils are stretched out of their deformed position. A current is then made to pass through the circuit that heat up the coil, which in turn makes the robot to return back to its original condition that would contract similar to muscles and fold the robots’ outer triangles in the center. Stopping the current lowers the triangles back down. The power for the robots is conveyed wirelessly via electromagnetic power transmission, as per Science Daily.

The lead author Mustafa Boyvat said, “Not only are our robots' folding motions repeatable, we can control when and where they happen, which enables more complex movements.”

This invention can prove to be very beneficial for example; it could be used as a replacement for endoscopy as the patient could swallow the micro-robot where it will perform its duties. Other than that, with the help of a larger coil, the robot could also be used for allowing wireless and battery-free communication between various smart objects in a house.

According to their research published in Science Robotics, the robots were created in different sizes from a quarter-sized flat tetrahedral robot to a hand-sized ship robot created using folded paper.

Harvard University’s website quoted Boyvat saying, “There is still room for miniaturization. We don't think we went to the limit of how small these can be, and we're excited to further develop our designs for biomedical applications.”